Re: Learning Python now coming from Perl
Roy Smith [EMAIL PROTECTED] wrote:
In article [EMAIL PROTECTED],
Nick Craig-Wood [EMAIL PROTECTED] wrote:
My favourite mistake when I made the transition was calling methods
without parentheses. In perl it is common to call methods without
parentheses - in python this does absolutely nothing! pychecker does
warn about it though.
perl - $object-method
python - object.method()
On the other hand, leaving out the parens returns the function itself,
which you can then call later. I've often used this to create data-driven
logic.
I didn't say it wasn't useful, just that if you came from Perl like I
did, it is an easy mistake to make ;-)
For example, I'm currently working on some code that marshals objects of
various types to a wire protocol. I've got something like:
encoders = {
SM_INT: write_int,
SM_SHORT: write_short,
SM_FLOAT: write_float,
# and so on
}
class AnyVal:
def __init__(self, type, value):
self.type = type
self.value = value
def write_anyval(any):
encoders[any.type](any.value)
The fact that functions are objects which can be assigned and stored in
containers makes this easy to do.
OO lore says whenever you see a type field in an instance you've gone
wrong - types should be represented by what sort of object you've got,
not by a type field.
Eg http://www.soberit.hut.fi/mmantyla/BadCodeSmellsTaxonomy.htm
The situation where switch statements or type codes are needed
should be handled by creating subclasses.
Here is my first iteration (untested)
class AnyVal:
def __init__(self, value):
self.value = value
def write(self):
raise NotImplementedError()
class IntVal(AnyVal):
def write(self):
# write_int code
class ShortVal(AnyVal):
def write(self):
# write_short code
class FloatVal(AnyVal):
def write(self):
# write_float code
Then to write an AnyVal you just call any.write()
The initialisation of the AnyVals then becomes
from AnyVal(int_expression, SM_INT)
to IntVal(int_expression)
However, if the types of the expressions aren't known until run time,
then use a dict of class types
AnyValRegistry = {
SM_INT: IntVal,
SM_SHORT: ShortVal,
SM_FLOAT: FloatVal,
# and so on
}
And initialise AnyVal objects thus
any = AnyValRegistry[type](value)
This smells of code duplication though and a real potential for a
mismatch between the AnyValRegistry and the actual classes.
I'd probably generalise this by putting the type code in the class and
use a __metaclass__ to autogenerate the AnyValRegistry dict which
would then become an attribute of AnyClass
Eg (slightly tested)
SM_INT=1
SM_SHORT=2
SM_FLOAT=3
class AnyVal(object):
TYPE = None
registry = {}
class __metaclass__(type):
def __init__(cls, name, bases, dict):
cls.registry[cls.TYPE] = cls
def __init__(self, value):
self.value = value
@classmethod
def new(cls, type_code, value):
Factory function to generate the correct subclass of AnyVal by type
code
return cls.registry[type_code](value)
def write(self):
raise NotImplementedError()
class IntVal(AnyVal):
TYPE = SM_INT
def write(self):
# write_int code
print int, self.value
class ShortVal(AnyVal):
TYPE = SM_SHORT
def write(self):
# write_short code
print short, self.value
class FloatVal(AnyVal):
TYPE = SM_FLOAT
def write(self):
# write_float code
print float, self.value
You then make new objects with any = AnyVal.new(type_code, value) and
write them with any.write()
Anyone can add a subclass of AnyVal and have it added to the
AnyVal.registry which is neat.
any = AnyVal.new(SM_SHORT, 1)
any
__main__.ShortVal object at 0xb7e3776c
any.write()
short 1
any = AnyVal.new(SM_FLOAT, 1.8)
any
__main__.FloatVal object at 0xb7e37a6c
any.write()
float 1.8
You could also override __new__ so you could write AnyVal(type_code,
value) to create the object of a new type. I personally don't think
its is worth it - a factory function is nice and obvious and show
exactly what is going on.
--
Nick Craig-Wood [EMAIL PROTECTED] -- http://www.craig-wood.com/nick
--
http://mail.python.org/mailman/listinfo/python-list
Re: Learning Python now coming from Perl
Nick Craig-Wood [EMAIL PROTECTED] wrote: On the other hand, leaving out the parens returns the function itself, which you can then call later. I've often used this to create data-driven logic. I didn't say it wasn't useful, just that if you came from Perl like I did, it is an easy mistake to make ;-) Agreed. OO lore says whenever you see a type field in an instance you've gone wrong - types should be represented by what sort of object you've got, not by a type field. OO lore lives in an ivory tower sometimes :-) I'm working with an existing system, where objects are marshaled on the wire as type codes followed by a type-specific number of bytes of data. Internally, it calls these AnyVals and the concept is pervasive in the architecture. I could work within the existing architecture, or I could try to fight it. Yes, I could get rid of the dispatch table and create 20 or 30 classes to represent all the possible types. I'd end up with several times as much code, most of it boilerplate. Instead of having a dispatch table of read/write functions, I'd have a dispatch table of classes, each of which has a read method and a write method. It doesn't buy anything, and I'd still have the type codes exposed because I need them to read and write values to the wire. -- http://mail.python.org/mailman/listinfo/python-list
Re: Learning Python now coming from Perl
On Sun, 2008-12-07 at 11:05 +0900, Bertilo Wennergren wrote: Aahz wrote: In article [EMAIL PROTECTED], Bertilo Wennergren [EMAIL PROTECTED] wrote: I don't suppose there is any introductory material out there that is based on Python 3000 and that is also geared at people with a Perl background? Too early for that I guess.. Honestly, the differences between 2.x and 3.0 are small enough that it doesn't much matter, as long as you're not the kind of person who gets put off by little problems. Because so much material is for 2.x, you may be better off just learning 2.x first and then moving to 3.x. The main reason I waited until Python 3000 came out is the new way Unicode is handled. The old way seemed really broken to me. Much of what I do when I program consists of juggling Unicode text (real Unicode text with lots of actual characters outside of Latin 1). So in my case learning version 2.x first might not be very convenient. I'd just get bogged down with the strange way 2.x handles such data. I'd rather skip that completely and just go with the Unicode handling in 3.0. I've actually found python's unicode handling quite strong. I will grant that it is not intuitive, but once you have learned it, it is clear, comprehensive, and sensible. It is by no means broken, or half-heartedly supported. The drawback is that you have to explicitly use it. It doesn't happen by default. For starters, only using str objects for input and output. As soon as you get them, decode them to unicode. And at the last minute, when writing them, encode them to your favorite encoding. Better yet, use codecs.open(file, encoding='utf-16') in place of open(file), pass an encoding argument, and be done with it. When you create strings in your code, always use u'stuff' rather than 'stuff' and ur'stu\ff' rather than r'stu\ff'. If you work with unicode on a daily basis, it shouldn't be hard to master. There are several good tutorials on the web. Cheers, Cliff -- http://mail.python.org/mailman/listinfo/python-list
Re: Learning Python now coming from Perl
Bertilo Wennergren [EMAIL PROTECTED] wrote: I'm planning to start learning Python now, using Python 3000. I have no previous Python skills, but I now Perl pretty well. I'm also well experienced with JavaScript. Any pointers and tips how I should go about getting into Python? Read Dive Into Python while following along with your keyboard. ( http://www.diveintopython.org/ free online or paper edition from your favourite bookseller ) My favourite mistake when I made the transition was calling methods without parentheses. In perl it is common to call methods without parentheses - in python this does absolutely nothing! pychecker does warn about it though. perl - $object-method python - object.method() -- Nick Craig-Wood [EMAIL PROTECTED] -- http://www.craig-wood.com/nick -- http://mail.python.org/mailman/listinfo/python-list
Re: Learning Python now coming from Perl
In article [EMAIL PROTECTED],
Nick Craig-Wood [EMAIL PROTECTED] wrote:
My favourite mistake when I made the transition was calling methods
without parentheses. In perl it is common to call methods without
parentheses - in python this does absolutely nothing! pychecker does
warn about it though.
perl - $object-method
python - object.method()
On the other hand, leaving out the parens returns the function itself,
which you can then call later. I've often used this to create data-driven
logic.
For example, I'm currently working on some code that marshals objects of
various types to a wire protocol. I've got something like:
encoders = {
SM_INT: write_int,
SM_SHORT: write_short,
SM_FLOAT: write_float,
# and so on
}
class AnyVal:
def __init__(self, type, value):
self.type = type
self.value = value
def write_anyval(any):
encoders[any.type](any.value)
The fact that functions are objects which can be assigned and stored in
containers makes this easy to do.
--
http://mail.python.org/mailman/listinfo/python-list
Learning Python now coming from Perl
I'm planning to start learning Python now, using Python 3000. I have no previous Python skills, but I now Perl pretty well. I'm also well experienced with JavaScript. Any pointers and tips how I should go about getting into Python? -- Bertilo Wennergren http://bertilow.com -- http://mail.python.org/mailman/listinfo/python-list
Re: Learning Python now coming from Perl
In article [EMAIL PROTECTED], Bertilo Wennergren [EMAIL PROTECTED] wrote: I'm planning to start learning Python now, using Python 3000. I have no previous Python skills, but I now Perl pretty well. I'm also well experienced with JavaScript. Any pointers and tips how I should go about getting into Python? I assume you use Perl to solve real problems in whatever job you do. My recommendation would be the next time some problem comes up that you would normally solve with Perl, try doing it in Python. Having a real task that you need to accomplish is a great way to focus the mind. For your first project, pick something that's small enough that you think you could tackle it in under 50 lines of Perl. One of the very first things you'll probably discover that's different between Perl and Python is how they handle string pattern matching. In Perl, it's a built in part of the language syntax. In Python, you use the re module. The regular expressions themselves are the same, but the mechanism you use to apply them to input text is quite different. -- http://mail.python.org/mailman/listinfo/python-list
Re: Learning Python now coming from Perl
Roy Smith wrote: Bertilo Wennergren [EMAIL PROTECTED] wrote: I'm planning to start learning Python now, using Python 3000. I have no previous Python skills, but I now Perl pretty well. I'm also well experienced with JavaScript. Any pointers and tips how I should go about getting into Python? I assume you use Perl to solve real problems in whatever job you do. My recommendation would be the next time some problem comes up that you would normally solve with Perl, try doing it in Python. Having a real task that you need to accomplish is a great way to focus the mind. For your first project, pick something that's small enough that you think you could tackle it in under 50 lines of Perl. Good advice. One of the very first things you'll probably discover that's different between Perl and Python is how they handle string pattern matching. In Perl, it's a built in part of the language syntax. In Python, you use the re module. The regular expressions themselves are the same, but the mechanism you use to apply them to input text is quite different. Thanks. I don't suppose there is any introductory material out there that is based on Python 3000 and that is also geared at people with a Perl background? Too early for that I guess.. -- Bertilo Wennergren http://bertilow.com -- http://mail.python.org/mailman/listinfo/python-list
Re: Learning Python now coming from Perl
Bertilo Wennergren wrote: Roy Smith wrote: Bertilo Wennergren [EMAIL PROTECTED] wrote: I'm planning to start learning Python now, using Python 3000. I have no previous Python skills, but I now Perl pretty well. I'm also well experienced with JavaScript. Any pointers and tips how I should go about getting into Python? I assume you use Perl to solve real problems in whatever job you do. My recommendation would be the next time some problem comes up that you would normally solve with Perl, try doing it in Python. Having a real task that you need to accomplish is a great way to focus the mind. For your first project, pick something that's small enough that you think you could tackle it in under 50 lines of Perl. Good advice. One of the very first things you'll probably discover that's different between Perl and Python is how they handle string pattern matching. In Perl, it's a built in part of the language syntax. In Python, you use the re module. The regular expressions themselves are the same, but the mechanism you use to apply them to input text is quite different. Thanks. I don't suppose there is any introductory material out there that is based on Python 3000 and that is also geared at people with a Perl background? Too early for that I guess.. This is from a post within the last few days: http://www.qtrac.eu/pyqtbook.html Colin W. -- http://mail.python.org/mailman/listinfo/python-list
Re: Learning Python now coming from Perl
On Sat, 06 Dec 2008 08:50:20 -0500, Roy Smith wrote: For your first project, pick something that's small enough that you think you could tackle it in under 50 lines of Perl. Is there anything which *can't* be written in under 50 lines of Perl? :-) One of the very first things you'll probably discover that's different between Perl and Python is how they handle string pattern matching. In Perl, it's a built in part of the language syntax. In Python, you use the re module. The regular expressions themselves are the same, but the mechanism you use to apply them to input text is quite different. Also, Perl REs are faster than Python REs, or so I'm told. Between the speed and the convenience, Perl programmers tend to use RE's for everything they can. Python programmers tend to use REs only for problems that *should* be solved with REs rather than *can* be solved with a RE. Well, I say tend, but in truth we get our fair share of questions like Hi, how do I factorize a 20 digit number with a regular expression? too. Probably the biggest difference is that in Python, you always refer to objects the same way, regardless of what sort of data they contain. Regardless of whether x is a scalar or a vector, you always call it just plain x. -- Steven -- http://mail.python.org/mailman/listinfo/python-list
Re: Learning Python now coming from Perl
In article [EMAIL PROTECTED], Bertilo Wennergren [EMAIL PROTECTED] wrote: I don't suppose there is any introductory material out there that is based on Python 3000 and that is also geared at people with a Perl background? Too early for that I guess.. Honestly, the differences between 2.x and 3.0 are small enough that it doesn't much matter, as long as you're not the kind of person who gets put off by little problems. Because so much material is for 2.x, you may be better off just learning 2.x first and then moving to 3.x. -- Aahz ([EMAIL PROTECTED]) * http://www.pythoncraft.com/ It is easier to optimize correct code than to correct optimized code. --Bill Harlan -- http://mail.python.org/mailman/listinfo/python-list
Re: Learning Python now coming from Perl
I fully agree with Roy's answer. COding small tasks is a good starting point. For quite some time you'll be of course less efficient than with your previous language, but that's part of the learning curve, isn't it. I guess you'll learn the syntax rather quickly. What's more painful is to learn which functianilty is in which library and which library exists. There's of course a lot of online documentation, but often you find answers to trivial python questions fastest with Google: for example: search for something like python string reverse example And there's of course this newsgroup whenever you're stuck with a 'missing' feature, (though mostly the features aren't missing, but just a little different) bye N Roy Smith wrote: In article [EMAIL PROTECTED], Bertilo Wennergren [EMAIL PROTECTED] wrote: I'm planning to start learning Python now, using Python 3000. I have no previous Python skills, . . . I assume you use Perl to solve real problems in whatever job you do. My recommendation would be the next time some problem comes up that you would normally solve with Perl, try doing it in Python. Having a real task that you need to accomplish is a great way to focus the mind. For your first project, pick something that's small enough that you think you could tackle it in under 50 lines of Perl. One of the very first things you'll probably discover that's different between Perl and Python is how they handle string pattern matching. In Perl, it's a built in part of the language syntax. In Python, you use the re module. The regular expressions themselves are the same, but the mechanism you use to apply them to input text is quite different. -- http://mail.python.org/mailman/listinfo/python-list
Re: Learning Python now coming from Perl
In article [EMAIL PROTECTED], [EMAIL PROTECTED] (Aahz) wrote: In article [EMAIL PROTECTED], Bertilo Wennergren [EMAIL PROTECTED] wrote: I don't suppose there is any introductory material out there that is based on Python 3000 and that is also geared at people with a Perl background? Too early for that I guess.. Honestly, the differences between 2.x and 3.0 are small enough that it doesn't much matter, as long as you're not the kind of person who gets put off by little problems. Because so much material is for 2.x, you may be better off just learning 2.x first and then moving to 3.x. I'm not sure I agree. If you're starting out, you might as well learn the new stuff. Then there's no need to unlearn the old way. Using material meant for 2.x is likely to lead to confusion. If you don't know either, you'll never know if something isn't working as described because you're doing it wrong or if it's just not the same as it used to be. When everything is new, what seem like little stumbling blocks to experts become total blockers to people starting from zero. -- http://mail.python.org/mailman/listinfo/python-list
Re: Learning Python now coming from Perl
News123 wrote: What's more painful is to learn which functianilty is in which library and which library exists. cut Yes and one mistake I still often find myself doing is, when confronted with a particular problem, that I write some helper code to deal with it. Of course later on I discover that there is a standard module or built-in that does exactly what I want and better. :-) Somehow in the heat of the moment my mind is not thinking 'there must be something out there which does what I want' but rather 'hmmm I think I can do it this way, clicker-di-click'. In my opinion it is a positive attribute to the language that it makes solving problems so easy that you forget about searching for solutions. Maybe python should prompt every 10 lines of code a message saying 'Are you sure this can not be done with a built-in?' Most of the time it will be right anyway :-) -- mph -- http://mail.python.org/mailman/listinfo/python-list
Re: Learning Python now coming from Perl
In article [EMAIL PROTECTED], Steven D'Aprano [EMAIL PROTECTED] wrote: On Sat, 06 Dec 2008 08:50:20 -0500, Roy Smith wrote: For your first project, pick something that's small enough that you think you could tackle it in under 50 lines of Perl. Is there anything which *can't* be written in under 50 lines of Perl? [...] Also, Perl REs are faster than Python REs, or so I'm told. Between the speed and the convenience, Perl programmers tend to use RE's for everything they can. Python programmers tend to use REs only for problems that *should* be solved with REs rather than *can* be solved with a RE. Well, as an old-time unix hacker (who learned REs long before Perl existed), my question to you would be, Is there any problem which *shouldn't* be solved with an RE? :-) It's easy to go nuts with REs, and create write-only code. On the other hand, they are an extremely powerful tool. If you are wise in the ways of RE-fu, they can not only be the most compact way to write something, but also the most efficient and even the most comprehensible. Unfortunately, REs seem to be regarded as some kind of monster these days and few people take the time to master them fully. Which is a shame. One really nice feature of REs in Python is the VERBOSE flag. It lets you write some way-complicated REs in a way which is still easy for somebody to read and understand. Python's raw strings, and triple-quoted strings, also help reduce the sea of backslashes which often make REs seem much worse than they really are. One of the reasons REs don't get used in Python as much as in Perl is because strings have useful methods like startswith(), endswith(), and split(), and also the in operator. These combine to give you easy ways to do many things you might otherwise do with REs. -- http://mail.python.org/mailman/listinfo/python-list
Re: Learning Python now coming from Perl
On Dec 6, 5:00 am, Bertilo Wennergren [EMAIL PROTECTED] wrote: I'm planning to start learning Python now, using Python 3000. I have no previous Python skills, but I now Perl pretty well. I'm also well experienced with JavaScript. Any pointers and tips how I should go about getting into Python? -- Bertilo Wennergren http://bertilow.com There's a lot of hoopla about Py3k being different, incompatible with Py2.x. However, you have to keep in mind that this matters most of all to old, large programs, which will need to be changed if one would like to run them on Py3k. For learning the differences don't matter much. If you learn to code in py2.x for half a year, you will be able to pick up on most of the differences and transfer to py3k in a few days. If you find good docs on py2.x go ahead and use them and don't worry. -- http://mail.python.org/mailman/listinfo/python-list
Re: Learning Python now coming from Perl
On Dec 6, 12:30 pm, Roy Smith [EMAIL PROTECTED] wrote: In article [EMAIL PROTECTED], [EMAIL PROTECTED] (Aahz) wrote: In article [EMAIL PROTECTED], Bertilo Wennergren [EMAIL PROTECTED] wrote: I don't suppose there is any introductory material out there that is based on Python 3000 and that is also geared at people with a Perl background? Too early for that I guess.. Honestly, the differences between 2.x and 3.0 are small enough that it doesn't much matter, as long as you're not the kind of person who gets put off by little problems. Because so much material is for 2.x, you may be better off just learning 2.x first and then moving to 3.x. I'm not sure I agree. If you're starting out, you might as well learn the new stuff. Then there's no need to unlearn the old way. One disadvantage of learning Python 3 first is the availability of third-party libraries (especially extension libraries), most of which will not be updated for Python 3.x for quite a while. Also, I don't think it's really advisable to be completely ignorant of the 2.x difference even if one intends to start with 3.0. There is a lot of code and material out there for 2.x, and until these start to be widely available for 3.x, people will sometimes have to make do with the 2.x stuff. Carl Banks -- http://mail.python.org/mailman/listinfo/python-list
Re: Learning Python now coming from Perl
On Sat, 06 Dec 2008 14:15:28 -0500, Roy Smith wrote: In article [EMAIL PROTECTED], Steven D'Aprano [EMAIL PROTECTED] wrote: On Sat, 06 Dec 2008 08:50:20 -0500, Roy Smith wrote: For your first project, pick something that's small enough that you think you could tackle it in under 50 lines of Perl. Is there anything which *can't* be written in under 50 lines of Perl? [...] Also, Perl REs are faster than Python REs, or so I'm told. Between the speed and the convenience, Perl programmers tend to use RE's for everything they can. Python programmers tend to use REs only for problems that *should* be solved with REs rather than *can* be solved with a RE. Well, as an old-time unix hacker (who learned REs long before Perl existed), my question to you would be, Is there any problem which *shouldn't* be solved with an RE? :-) I think you've answered your own question: One of the reasons REs don't get used in Python as much as in Perl is because strings have useful methods like startswith(), endswith(), and split(), and also the in operator. These combine to give you easy ways to do many things you might otherwise do with REs. Also: * splitting pathnames and file extensions * dealing with arbitrarily nested parentheses * any time you need a full-blown parser (e.g. parsing HTML or XML) * sanitizing untrusted user input (I bet I can think of *every* bad input and detect them all with this regex!) * validating email addresses http://northernplanets.blogspot.com/2007/03/how-not-to-validate-email-addresses.html * testing prime numbers http://jtauber.com/blog/2007/03/18/python_primality_regex/ * doing maths http://blog.stevenlevithan.com/archives/algebra-with-regexes http://weblogs.asp.net/rosherove/archive/2004/11/08/253992.aspx There's probably more. -- Steven -- http://mail.python.org/mailman/listinfo/python-list
Re: Learning Python now coming from Perl
Perl Cookbook for Python Programmers: http://pleac.sourceforge.net/pleac_python/index.html P3K as starting point (slight cringe) as long as you know the caveats. I'm of the mind as Christopher with regard to how Python 3.0 has been released on Python.org: I don't think that Python 3.0 is a bad thing. But that it's displayed so prominently on the Python web site, without any kind of warning that it's not going to work with 99% of the Python code out there, scares the hell out of me. People are going to download and install 3.0 by default, and nothing's going to work. They're going to complain, and many are going to simply walk away. - Christopher Lenz Python3 is beautiful, and I am totally with James Bennet http://www.b-list.org/weblog/2008/dec/05/python-3000/ That said I would suggest you learn the whole history of the Py3K project and its 19+ years of 20/20 hindsight on what works well and what doesn't so you can if you want to jump right into Python3 fully informed on why it is the way it is and why you need to wait for 3rd party libraries to catch up and release a Python 3 compatible version and why all the Internal libraries are no worry except for the fact some of them have disappeared in the cleanup or merged into a single library. Then you can make sense of all the 2.x books and posts and know where to start when trying to apply it to Python 3. Cheers, PN (Python 2.5.2, Stackless Python 2.5.2, Python 2.6 and Python 3.0 on my box) P.S. Look into iPython as your new favourtie shell and virtualenv to help you keep all your projects straight and you'll be very productive in no time =) 2008/12/7 Bertilo Wennergren [EMAIL PROTECTED]: I'm planning to start learning Python now, using Python 3000. I have no previous Python skills, but I now Perl pretty well. I'm also well experienced with JavaScript. Any pointers and tips how I should go about getting into Python? -- http://mail.python.org/mailman/listinfo/python-list
Re: Learning Python now coming from Perl
In article [EMAIL PROTECTED], Steven D'Aprano [EMAIL PROTECTED] wrote: Well, as an old-time unix hacker (who learned REs long before Perl existed), my question to you would be, Is there any problem which *shouldn't* be solved with an RE? :-) One of the reasons REs don't get used in Python as much as in Perl is because strings have useful methods like startswith(), endswith(), and split(), and also the in operator. These combine to give you easy ways to do many things you might otherwise do with REs. I agree, I'm going through the new book Python for Unix and Linux Administration now and although in general I like what they say, they take you through the built in string functions and then introduce REs and end the chapter leaving the reader with the impression that REs are the better solution and I only agree with the case of the problem/program they presented. However I used the built ins more effectively using the indexes returned within the string and I've built plenty of scripts that did not need to move to REs to perform the text/file processing that I did. This intermediate use of string built-in functions was missing between the first string-function and RE versions of code and imho it is not letting the readers see that string-functions are even more powerful than the reader is lead to believe and that REs are pushed more towards edge cases than the impression the reader seems to be left with which is to use REs more. At least if you push REs inform the readers where to get the a RE GUI builder written in Python so they can build and *test* the complex and unwieldy REs to perform anything beyond the basic pattern searches. Cheers, PN -- http://mail.python.org/mailman/listinfo/python-list
Re: Learning Python now coming from Perl
Aahz wrote: In article [EMAIL PROTECTED], Bertilo Wennergren [EMAIL PROTECTED] wrote: I don't suppose there is any introductory material out there that is based on Python 3000 and that is also geared at people with a Perl background? Too early for that I guess.. Honestly, the differences between 2.x and 3.0 are small enough that it doesn't much matter, as long as you're not the kind of person who gets put off by little problems. Because so much material is for 2.x, you may be better off just learning 2.x first and then moving to 3.x. The main reason I waited until Python 3000 came out is the new way Unicode is handled. The old way seemed really broken to me. Much of what I do when I program consists of juggling Unicode text (real Unicode text with lots of actual characters outside of Latin 1). So in my case learning version 2.x first might not be very convenient. I'd just get bogged down with the strange way 2.x handles such data. I'd rather skip that completely and just go with the Unicode handling in 3.0. -- Bertilo Wennergren http://bertilow.com -- http://mail.python.org/mailman/listinfo/python-list
Re: Learning Python now coming from Perl
Bertilo Wennergren wrote: Aahz wrote: In article [EMAIL PROTECTED], Bertilo Wennergren [EMAIL PROTECTED] wrote: I don't suppose there is any introductory material out there that is based on Python 3000 and that is also geared at people with a Perl background? Too early for that I guess.. Honestly, the differences between 2.x and 3.0 are small enough that it doesn't much matter, as long as you're not the kind of person who gets put off by little problems. Because so much material is for 2.x, you may be better off just learning 2.x first and then moving to 3.x. The main reason I waited until Python 3000 came out is the new way Unicode is handled. The old way seemed really broken to me. Much of what I do when I program consists of juggling Unicode text (real Unicode text with lots of actual characters outside of Latin 1). So in my case learning version 2.x first might not be very convenient. I'd just get bogged down with the strange way 2.x handles such data. I'd rather skip that completely and just go with the Unicode handling in 3.0. I wouldn't have said it was broken, it's just that it was a later addition to the language and backwards compatibility is important. Tidying things which would break backwards compatibility in a big way was deliberately left to a major version, Python 3. -- http://mail.python.org/mailman/listinfo/python-list
Re: Learning Python now coming from Perl
In article [EMAIL PROTECTED], Python Nutter [EMAIL PROTECTED] wrote: At least if you push REs inform the readers where to get the a RE GUI builder written in Python so they can build and *test* the complex and unwieldy REs to perform anything beyond the basic pattern searches. Oh, my, I think my brain's about to explode. A RE GUI builder? Cough, gasp, sputter. This is literally the first time I've ever heard of such a thing, and it's leaving a bad taste in my mouth. RE is the last bastion of Real Programmers. Real Programmers don't use GUI builders. Using a GUI to build an RE is like trying to program by pushing little UMLish things around with a mouse. It's Just Wrong. -- http://mail.python.org/mailman/listinfo/python-list
Re: Learning Python now coming from Perl
In article [EMAIL PROTECTED], Bertilo Wennergren [EMAIL PROTECTED] wrote: The main reason I waited until Python 3000 came out is the new way Unicode is handled. The old way seemed really broken to me. Much of what I do when I program consists of juggling Unicode text (real Unicode text with lots of actual characters outside of Latin 1). So in my case learning version 2.x first might not be very convenient. I'd just get bogged down with the strange way 2.x handles such data. I'd rather skip that completely and just go with the Unicode handling in 3.0. Sounds like you have a good use-case for 3.0 -- go to it! -- Aahz ([EMAIL PROTECTED]) * http://www.pythoncraft.com/ It is easier to optimize correct code than to correct optimized code. --Bill Harlan -- http://mail.python.org/mailman/listinfo/python-list
Re: Coming from Perl
Amer Neely wrote: Bryan Olson wrote: Amer Neely wrote: I don't have shell access but I can run 'which python' from a Perl script, and I will try the different shebang line you suggested. And after trying it, Amer Neely reported: I tried `which python` and `whereis python` and got 0 back as a result. So it seems Python is not installed at all. Probably right, but just to be thorough... Since you do not have shell access, I'm guessing you are running these within a Perl cgi script, and getting the results via a browser. Is that right? Yes. Can you backtick other commands? What do you get if you run `which perl` the same way? How about `whoami`, `whereis sh`, and `which nosuchthingas5748614`? Can you list /, /bin and /usr/bin? I just looked at my code and tried something else: @SysCmd=which python; system(@SysCmd); and it came back /usr/local/bin/python How did you learn that this system could run your Perl scripts? Can that source give us anything to go on here? If Python is not installed, do you have some avenue for requesting it? We're down to long shots. Still, hosts that support Perl but will not support Python are getting to be the rare. I've asked my host to put in a request for it. So it seems python IS installed, but not where I thought it was. I just tried my script with the new path, but still got a 500 server error. Can I trap errors to a file locally? You could try putting an ErrorLog directive in your local .htaccess file. http://httpd.apache.org/docs/1.3/logs.html#errorlog regards Steve -- Steve Holden+1 571 484 6266 +1 800 494 3119 Holden Web LLC/Ltd http://www.holdenweb.com Skype: holdenweb http://del.icio.us/steve.holden Sorry, the dog ate my .sigline -- http://mail.python.org/mailman/listinfo/python-list
Re: Coming from Perl
Amer Neely wrote: I don't have shell access but I can run 'which python' from a Perl script, and I will try the different shebang line you suggested. And after trying it, Amer Neely reported: I tried `which python` and `whereis python` and got 0 back as a result. So it seems Python is not installed at all. Probably right, but just to be thorough... Since you do not have shell access, I'm guessing you are running these within a Perl cgi script, and getting the results via a browser. Is that right? Can you backtick other commands? What do you get if you run `which perl` the same way? How about `whoami`, `whereis sh`, and `which nosuchthingas5748614`? Can you list /, /bin and /usr/bin? How did you learn that this system could run your Perl scripts? Can that source give us anything to go on here? If Python is not installed, do you have some avenue for requesting it? We're down to long shots. Still, hosts that support Perl but will not support Python are getting to be the rare. -- --Bryan -- http://mail.python.org/mailman/listinfo/python-list
Re: Coming from Perl
Bryan Olson wrote: Amer Neely wrote: I don't have shell access but I can run 'which python' from a Perl script, and I will try the different shebang line you suggested. And after trying it, Amer Neely reported: I tried `which python` and `whereis python` and got 0 back as a result. So it seems Python is not installed at all. Probably right, but just to be thorough... Since you do not have shell access, I'm guessing you are running these within a Perl cgi script, and getting the results via a browser. Is that right? Yes. Can you backtick other commands? What do you get if you run `which perl` the same way? How about `whoami`, `whereis sh`, and `which nosuchthingas5748614`? Can you list /, /bin and /usr/bin? I just looked at my code and tried something else: @SysCmd=which python; system(@SysCmd); and it came back /usr/local/bin/python How did you learn that this system could run your Perl scripts? Can that source give us anything to go on here? If Python is not installed, do you have some avenue for requesting it? We're down to long shots. Still, hosts that support Perl but will not support Python are getting to be the rare. I've asked my host to put in a request for it. So it seems python IS installed, but not where I thought it was. I just tried my script with the new path, but still got a 500 server error. Can I trap errors to a file locally? -- Amer Neely w: www.webmechanic.softouch.on.ca/ Perl | MySQL programming for all data entry forms. Others make web sites. We make web sites work! -- http://mail.python.org/mailman/listinfo/python-list
Re: Coming from Perl
Paddy wrote: On Sep 13, 1:30 am, Amer Neely [EMAIL PROTECTED] wrote: I'm a complete newbie with Python, but have several years experience with Perl in a web environment. A question I have, if someone here is familiar with Perl, does Python have something like Perl's 'here document'? I've just searched and read some postings on generating HTML but they all seem to refer to various template utilities. Is this the only way, or am I missing something? I'm used to generating X/HTML by hand, which makes the here document in Perl ideal for me. Also, many times a client already existing HTML code that I can use in a script. Hi Amer, Just as an aside, you might find this helpful: http://wiki.python.org/moin/PerlPhrasebook It has perl code with python equivalents/notes. Hello Paddy, Thanks for that link - it does look quite useful. -- Amer Neely w: www.webmechanic.softouch.on.ca/ Perl | MySQL programming for all data entry forms. Others make web sites. We make web sites work! -- http://mail.python.org/mailman/listinfo/python-list
Re: Coming from Perl - SOLVED
I V wrote: On Thu, 13 Sep 2007 23:49:32 -0400, Amer Neely wrote: In trying to track down why this script would not run on my host, it has to come to light that Python is installed, however the Apache module is not. So, short story is - I was flogging a dead horse. Which Apache module? You don't need any special modules (just the regular CGI one) to use python in a CGI script. That is an interesting observation. It does run under my Apache + Win2K at home, with no special configuration by me. All I'm going on is what the techs told me. So, you think it may be something else? I've changed and even eliminated the end-of-line chars in my print statements. Another poster (Bryan Olson) has suggested a few things to try as well so I will try those. I don't have shell access though, so the best I can do is execute shell commands from a Perl script. -- Amer Neely w: www.webmechanic.softouch.on.ca/ Perl | MySQL programming for all data entry forms. Others make web sites. We make web sites work! -- http://mail.python.org/mailman/listinfo/python-list
Re: Coming from Perl
Bryan Olson wrote: Amer Neely wrote: This seems to indicate that maybe my host needs to configure Apache to run python scripts? But I didn't need to do anything with mine. Another possibility: If it works on Windows but not Unix, check the end-of-line characters. Windows ends each line with the two character sequence carriage-return + newline, which in Python is \r\n. Unix uses newline alone, \n. Most Unixies will choke on a #! line with a carriage return. The Python interpreter will accept source files with either end-of-line on either system, but of course you'll not get that far unless the operating system respects the shebang line. Maybe you already checked that. Hmmm...other possiblities... Do you have shell access? Can you executing it directly from the shell? Do you get a Python error, or some other? Did you: chmod ugo+rx yourscript Is Python in /usr/bin? What does which python say? Generally, most experts seem to prefer: #!/usr/bin/env python You might try changing the the extension of your script from .py to .cgi. Windows uses the .py to choose the executable, but Unix does not care; it used the shebang line. Hmmm. These are interesting suggestions. Especially in light of a new wrinkle pointed out by [IV]. That being the script runs fine under my Apache at home with no special modules loaded. I don't have shell access but I can run 'which python' from a Perl script, and I will try the different shebang line you suggested. Thanks for the suggestions. -- Amer Neely w: www.webmechanic.softouch.on.ca/ Perl | MySQL programming for all data entry forms. Others make web sites. We make web sites work! -- http://mail.python.org/mailman/listinfo/python-list
Re: Coming from Perl
Bryan Olson wrote: Amer Neely wrote: This seems to indicate that maybe my host needs to configure Apache to run python scripts? But I didn't need to do anything with mine. Another possibility: If it works on Windows but not Unix, check the end-of-line characters. Windows ends each line with the two character sequence carriage-return + newline, which in Python is \r\n. Unix uses newline alone, \n. Most Unixies will choke on a #! line with a carriage return. The Python interpreter will accept source files with either end-of-line on either system, but of course you'll not get that far unless the operating system respects the shebang line. Maybe you already checked that. Hmmm...other possiblities... Do you have shell access? Can you executing it directly from the shell? Do you get a Python error, or some other? Did you: chmod ugo+rx yourscript Is Python in /usr/bin? What does which python say? Generally, most experts seem to prefer: #!/usr/bin/env python You might try changing the the extension of your script from .py to .cgi. Windows uses the .py to choose the executable, but Unix does not care; it used the shebang line. I tried `which python` and `whereis python` and got 0 back as a result. So it seems Python is not installed at all. -- Amer Neely w: www.webmechanic.softouch.on.ca/ Perl | MySQL programming for all data entry forms. Others make web sites. We make web sites work! -- http://mail.python.org/mailman/listinfo/python-list
Re: Coming from Perl - SOLVED
On Thu, 13 Sep 2007 23:49:32 -0400, Amer Neely wrote: In trying to track down why this script would not run on my host, it has to come to light that Python is installed, however the Apache module is not. So, short story is - I was flogging a dead horse. Which Apache module? You don't need any special modules (just the regular CGI one) to use python in a CGI script. -- http://mail.python.org/mailman/listinfo/python-list
Re: Coming from Perl
Amer Neely wrote: This seems to indicate that maybe my host needs to configure Apache to run python scripts? But I didn't need to do anything with mine. Another possibility: If it works on Windows but not Unix, check the end-of-line characters. Windows ends each line with the two character sequence carriage-return + newline, which in Python is \r\n. Unix uses newline alone, \n. Most Unixies will choke on a #! line with a carriage return. The Python interpreter will accept source files with either end-of-line on either system, but of course you'll not get that far unless the operating system respects the shebang line. Maybe you already checked that. Hmmm...other possiblities... Do you have shell access? Can you executing it directly from the shell? Do you get a Python error, or some other? Did you: chmod ugo+rx yourscript Is Python in /usr/bin? What does which python say? Generally, most experts seem to prefer: #!/usr/bin/env python You might try changing the the extension of your script from .py to .cgi. Windows uses the .py to choose the executable, but Unix does not care; it used the shebang line. -- --Bryan -- http://mail.python.org/mailman/listinfo/python-list
Re: Coming from Perl
TheFlyingDutchman wrote: On Sep 12, 5:30 pm, Amer Neely [EMAIL PROTECTED] wrote: I'm a complete newbie with Python, but have several years experience with Perl in a web environment. A question I have, if someone here is familiar with Perl, does Python have something like Perl's 'here document'? I've just searched and read some postings on generating HTML but they all seem to refer to various template utilities. Is this the only way, or am I missing something? I'm used to generating X/HTML by hand, which makes the here document in Perl ideal for me. Also, many times a client already existing HTML code that I can use in a script. -- Amer Neely w:www.webmechanic.softouch.on.ca/ Perl | MySQL programming for all data entry forms. Others make web sites. We make web sites work! I am not sure if this is what you are looking for, but Python has a special string with 3 quotes that I believe duplicates part of the functionality of a here document: myHmtlHeader = head attribute = abc titleMy Page/title /head print myHtmlHeader outputs: head attribute=abc titleMy Page/title /head Well, I have checked everything I can but I'm getting '500 Internal Server Error'. The log files aren't helpful: [Thu Sep 13 03:43:00 2007] [error] [client 24.235.184.39] Premature end of script headers: /home/softouch/public_html/cgi-bin/scratch/hello.py I can't even get it to run on my home PC running Apache + Win2K. Same error. My script: #!/usr/bin/python import cgitb; cgitb.enable(display=0, logdir=.) import sys sys.stderr = sys.stdout print Content-Type: text/html print print html body div align=centerfont style=font-family:verdana; size:18pxHello from Python/font/div br Goodbye. /body /html -- Amer Neely w: www.webmechanic.softouch.on.ca/ Perl | MySQL programming for all data entry forms. Others make web sites. We make web sites work! -- http://mail.python.org/mailman/listinfo/python-list
Re: Coming from Perl
Amer Neely wrote: TheFlyingDutchman wrote: On Sep 12, 5:30 pm, Amer Neely [EMAIL PROTECTED] wrote: I'm a complete newbie with Python, but have several years experience with Perl in a web environment. A question I have, if someone here is familiar with Perl, does Python have something like Perl's 'here document'? I've just searched and read some postings on generating HTML but they all seem to refer to various template utilities. Is this the only way, or am I missing something? I'm used to generating X/HTML by hand, which makes the here document in Perl ideal for me. Also, many times a client already existing HTML code that I can use in a script. -- Amer Neely w:www.webmechanic.softouch.on.ca/ Perl | MySQL programming for all data entry forms. Others make web sites. We make web sites work! I am not sure if this is what you are looking for, but Python has a special string with 3 quotes that I believe duplicates part of the functionality of a here document: myHmtlHeader = head attribute = abc titleMy Page/title /head print myHtmlHeader outputs: head attribute=abc titleMy Page/title /head Well, I have checked everything I can but I'm getting '500 Internal Server Error'. The log files aren't helpful: [Thu Sep 13 03:43:00 2007] [error] [client 24.235.184.39] Premature end of script headers: /home/softouch/public_html/cgi-bin/scratch/hello.py I can't even get it to run on my home PC running Apache + Win2K. Same error. My script: #!/usr/bin/python import cgitb; cgitb.enable(display=0, logdir=.) import sys sys.stderr = sys.stdout print Content-Type: text/html print print html body div align=centerfont style=font-family:verdana; size:18pxHello from Python/font/div br Goodbye. /body /html I should have added that it runs from the command line OK. -- Amer Neely w: www.webmechanic.softouch.on.ca/ Perl | MySQL programming for all data entry forms. Others make web sites. We make web sites work! -- http://mail.python.org/mailman/listinfo/python-list
Re: Coming from Perl
Amer Neely [EMAIL PROTECTED] writes: Well, I have checked everything I can but I'm getting '500 Internal Server Error'. This is the HTTP response code saying that the program that should have served the response document instead exited with an error. To debug, you should first run the program (or at least the part that you're trying to implement) *outside* the context of a web server. Do it at a command line, and any errors will show up as exception tracebacks. Only when you have something that performs correctly outside a web server context should you consider how to wrap it in that new (harder-to-debug) context. -- \What if the Hokey Pokey IS what it's all about? —anonymous | `\ | _o__) | Ben Finney -- http://mail.python.org/mailman/listinfo/python-list
Re: Coming from Perl
Ben Finney wrote: Amer Neely [EMAIL PROTECTED] writes: Well, I have checked everything I can but I'm getting '500 Internal Server Error'. This is the HTTP response code saying that the program that should have served the response document instead exited with an error. To debug, you should first run the program (or at least the part that you're trying to implement) *outside* the context of a web server. Do it at a command line, and any errors will show up as exception tracebacks. Only when you have something that performs correctly outside a web server context should you consider how to wrap it in that new (harder-to-debug) context. That is where I'm stuck. It runs fine on my home computer, but I don't have shell access to my hosted site. Can you or anyone see anything in the posted code that might be the cause? Why is it so much harder to debug? There is no syntax error that I can tell. I've set the file permissions to rwxr-xr-x. I've printed the correct content type. It's a simple print statement, as per several examples I've seen. Is it an Apache thing? I've not seen any mention in the documentation on that. -- Amer Neely w: www.webmechanic.softouch.on.ca/ Perl | MySQL programming for all data entry forms. Others make web sites. We make web sites work! -- http://mail.python.org/mailman/listinfo/python-list
Re: Coming from Perl
[Amer] Can you or anyone see anything in the posted code that might be the cause? #!/usr/bin/python import cgitb; cgitb.enable(display=0, logdir=.) import sys sys.stderr = sys.stdout print Content-Type: text/html print My guess would be that you don't have cgitb in your server environment, or that you have a bogus one. Rearrange things like this: #!/usr/bin/python print Content-Type: text/html print import sys sys.stderr = sys.stdout import cgitb; cgitb.enable(display=0, logdir=.) -- Richie Hindle [EMAIL PROTECTED] -- http://mail.python.org/mailman/listinfo/python-list
Re: Coming from Perl
Richie Hindle wrote: [Amer] Can you or anyone see anything in the posted code that might be the cause? #!/usr/bin/python import cgitb; cgitb.enable(display=0, logdir=.) import sys sys.stderr = sys.stdout print Content-Type: text/html print My guess would be that you don't have cgitb in your server environment, or that you have a bogus one. Rearrange things like this: #!/usr/bin/python print Content-Type: text/html print import sys sys.stderr = sys.stdout import cgitb; cgitb.enable(display=0, logdir=.) Nope. Same error. Is cgitb not in the standard distribution? Is it needed to print HTML? On my home PC I changed the Apache error logging to 'debug' and got this nugget: [Thu Sep 13 04:16:03 2007] [error] [client 0.0.0.0] (OS 2)The system cannot find the file specified. : couldn't create child process: 720002: hello.py I suspect it would be similar on my hosting server. Is this saying it can't find hello.py or one of the modules? -- Amer Neely w: www.webmechanic.softouch.on.ca/ Perl | MySQL programming for all data entry forms. Others make web sites. We make web sites work! -- http://mail.python.org/mailman/listinfo/python-list
Re: Coming from Perl
[Amer] #!/usr/bin/python [...] On my home PC [...] [Thu Sep 13 04:16:03 2007] [error] [client 0.0.0.0] (OS 2)The system cannot find the file specified. That's because on your home PC Python is somewhere like C:\Python25\python.exe, not /usr/bin/python. Are you sure /usr/bin/python is correct for your hosting environment? -- Richie Hindle [EMAIL PROTECTED] -- http://mail.python.org/mailman/listinfo/python-list
My first Python CGI (was: Coming from Perl)
In article [EMAIL PROTECTED], Amer Neely [EMAIL PROTECTED] wrote: Amer Neely wrote: TheFlyingDutchman wrote: On Sep 12, 5:30 pm, Amer Neely [EMAIL PROTECTED] wrote: I'm a complete newbie with Python, but have several years experience with Perl in a web environment. A question I have, if someone here is familiar with Perl, does Python have something like Perl's 'here document'? I've just searched and read some postings on generating HTML but they all seem to refer to various template utilities. Is this the only way, or am I missing something? I'm used to generating X/HTML by hand, which makes the here document in Perl ideal for me. Also, many times a client already existing HTML code that I can use in a script. -- Amer Neely w:www.webmechanic.softouch.on.ca/ Perl | MySQL programming for all data entry forms. Others make web sites. We make web sites work! I am not sure if this is what you are looking for, but Python has a special string with 3 quotes that I believe duplicates part of the functionality of a here document: myHmtlHeader = head attribute = abc titleMy Page/title /head print myHtmlHeader outputs: head attribute=abc titleMy Page/title /head Well, I have checked everything I can but I'm getting '500 Internal Server Error'. The log files aren't helpful: [Thu Sep 13 03:43:00 2007] [error] [client 24.235.184.39] Premature end of script headers: /home/softouch/public_html/cgi-bin/scratch/hello.py I can't even get it to run on my home PC running Apache + Win2K. Same error. My script: #!/usr/bin/python import cgitb; cgitb.enable(display=0, logdir=.) import sys sys.stderr = sys.stdout print Content-Type: text/html print print html body div align=centerfont style=font-family:verdana; size:18pxHello from Python/font/div br Goodbye. /body /html I should have added that it runs from the command line OK. . . . Yes, it should work fine. Do the things you'd do if it were Perl source: when you say it runs from the command line OK, do you mean invocation of /home/softouch/public_html/cgi-bin/scratch/hello.py gives sensible results? Does your Web server recognize that .py is a CGI extension? What are the permissions on /home/softouch/public_html/cgi-bin/scratch/hello.py? Might your server have an issue with Content-Type vs. Content-type? -- http://mail.python.org/mailman/listinfo/python-list
Re: Coming from Perl
Richie Hindle wrote: [Amer] #!/usr/bin/python [...] On my home PC [...] [Thu Sep 13 04:16:03 2007] [error] [client 0.0.0.0] (OS 2)The system cannot find the file specified. That's because on your home PC Python is somewhere like C:\Python25\python.exe, not /usr/bin/python. Are you sure /usr/bin/python is correct for your hosting environment? It's my understanding that the Windows shell doesn't pay much attention to the shebang line if the file type is associated with the proper application. But I tried your suggestion and got the same results. -- Amer Neely w: www.webmechanic.softouch.on.ca/ Perl | MySQL programming for all data entry forms. Others make web sites. We make web sites work! -- http://mail.python.org/mailman/listinfo/python-list
Re: Coming from Perl
Amer Neely wrote: Richie Hindle wrote: [Amer] #!/usr/bin/python [...] On my home PC [...] [Thu Sep 13 04:16:03 2007] [error] [client 0.0.0.0] (OS 2)The system cannot find the file specified. That's because on your home PC Python is somewhere like C:\Python25\python.exe, not /usr/bin/python. Are you sure /usr/bin/python is correct for your hosting environment? It's my understanding that the Windows shell doesn't pay much attention to the shebang line if the file type is associated with the proper application. But I tried your suggestion and got the same results. My BAD! I changed the shebang all right, but entered a typo. With the correct path it did work just fine. So, perhaps the path to python on my host is wrong? I got that one right from the techs. -- Amer Neely w: www.webmechanic.softouch.on.ca/ Perl | MySQL programming for all data entry forms. Others make web sites. We make web sites work! -- http://mail.python.org/mailman/listinfo/python-list
Re: Coming from Perl
Amer Neely wrote: Richie Hindle wrote: [Amer] #!/usr/bin/python [...] On my home PC [...] [Thu Sep 13 04:16:03 2007] [error] [client 0.0.0.0] (OS 2)The system cannot find the file specified. That's because on your home PC Python is somewhere like C:\Python25\python.exe, not /usr/bin/python. Are you sure /usr/bin/python is correct for your hosting environment? It's my understanding that the Windows shell doesn't pay much attention to the shebang line if the file type is associated with the proper application. But I tried your suggestion and got the same results. The Windows shell doesn't, but Apache does. (Haven't followed this thread closely, but I seem to remember it has to do with running CGI scripts). TJG -- http://mail.python.org/mailman/listinfo/python-list
Re: Coming from Perl
Tim Golden wrote: Amer Neely wrote: Richie Hindle wrote: [Amer] #!/usr/bin/python [...] On my home PC [...] [Thu Sep 13 04:16:03 2007] [error] [client 0.0.0.0] (OS 2)The system cannot find the file specified. That's because on your home PC Python is somewhere like C:\Python25\python.exe, not /usr/bin/python. Are you sure /usr/bin/python is correct for your hosting environment? It's my understanding that the Windows shell doesn't pay much attention to the shebang line if the file type is associated with the proper application. But I tried your suggestion and got the same results. See my reply to this post - I had a typo in the shebang line and it now works on my home PC. The Windows shell doesn't, but Apache does. (Haven't followed this thread closely, but I seem to remember it has to do with running CGI scripts). This seems to indicate that maybe my host needs to configure Apache to run python scripts? But I didn't need to do anything with mine. -- Amer Neely w: www.webmechanic.softouch.on.ca/ Perl | MySQL programming for all data entry forms. Others make web sites. We make web sites work! -- http://mail.python.org/mailman/listinfo/python-list
Re: Coming from Perl
On Sep 13, 1:30 am, Amer Neely [EMAIL PROTECTED] wrote: I'm a complete newbie with Python, but have several years experience with Perl in a web environment. A question I have, if someone here is familiar with Perl, does Python have something like Perl's 'here document'? I've just searched and read some postings on generating HTML but they all seem to refer to various template utilities. Is this the only way, or am I missing something? I'm used to generating X/HTML by hand, which makes the here document in Perl ideal for me. Also, many times a client already existing HTML code that I can use in a script. -- Amer Neely w:www.webmechanic.softouch.on.ca/ Perl | MySQL programming for all data entry forms. Others make web sites. We make web sites work! Hi Amer, Just as an aside, you might find this helpful: http://wiki.python.org/moin/PerlPhrasebook It has perl code with python equivalents/notes. - Paddy. -- http://mail.python.org/mailman/listinfo/python-list
Re: Coming from Perl - SOLVED
Amer Neely wrote: I'm a complete newbie with Python, but have several years experience with Perl in a web environment. A question I have, if someone here is familiar with Perl, does Python have something like Perl's 'here document'? I've just searched and read some postings on generating HTML but they all seem to refer to various template utilities. Is this the only way, or am I missing something? I'm used to generating X/HTML by hand, which makes the here document in Perl ideal for me. Also, many times a client already existing HTML code that I can use in a script. In trying to track down why this script would not run on my host, it has to come to light that Python is installed, however the Apache module is not. So, short story is - I was flogging a dead horse. Sorry for raising a non-issue folks. -- Amer Neely w: www.webmechanic.softouch.on.ca/ Perl | MySQL programming for all data entry forms. Others make web sites. We make web sites work! -- http://mail.python.org/mailman/listinfo/python-list
Coming from Perl
I'm a complete newbie with Python, but have several years experience with Perl in a web environment. A question I have, if someone here is familiar with Perl, does Python have something like Perl's 'here document'? I've just searched and read some postings on generating HTML but they all seem to refer to various template utilities. Is this the only way, or am I missing something? I'm used to generating X/HTML by hand, which makes the here document in Perl ideal for me. Also, many times a client already existing HTML code that I can use in a script. -- Amer Neely w: www.webmechanic.softouch.on.ca/ Perl | MySQL programming for all data entry forms. Others make web sites. We make web sites work! -- http://mail.python.org/mailman/listinfo/python-list
Re: Coming from Perl
Amer Neely [EMAIL PROTECTED] writes: A question I have, if someone here is familiar with Perl, does Python have something like Perl's 'here document'? I'm not sure exactly what behaviour you want, but Python accepts literal strings to be triple-quoted (i.e. delimited by pairs or ''' pairs), which allows you to freely use literal line feed and quote characters inside that string. URL:http://docs.python.org/ref/strings.html -- \ Are you pondering what I'm pondering? I think so, Brain, but | `\pants with horizontal stripes make me look chubby. -- _Pinky | _o__) and The Brain_ | Ben Finney -- http://mail.python.org/mailman/listinfo/python-list
Re: Coming from Perl
Ben Finney wrote: Amer Neely [EMAIL PROTECTED] writes: A question I have, if someone here is familiar with Perl, does Python have something like Perl's 'here document'? I'm not sure exactly what behaviour you want, but Python accepts literal strings to be triple-quoted (i.e. delimited by pairs or ''' pairs), which allows you to freely use literal line feed and quote characters inside that string. URL:http://docs.python.org/ref/strings.html I saw that and I guess that is the closest thing. In Perl I can do .. print EndHTML; html body Hello /body /html EndHTML In this case 'EndHTML' is a label, and I'm telling perl to print everything as is up to that label. -- Amer Neely w: www.webmechanic.softouch.on.ca/ Perl | MySQL programming for all data entry forms. Others make web sites. We make web sites work! -- http://mail.python.org/mailman/listinfo/python-list
Re: Coming from Perl
On Sep 12, 5:30 pm, Amer Neely [EMAIL PROTECTED] wrote: I'm a complete newbie with Python, but have several years experience with Perl in a web environment. A question I have, if someone here is familiar with Perl, does Python have something like Perl's 'here document'? I've just searched and read some postings on generating HTML but they all seem to refer to various template utilities. Is this the only way, or am I missing something? I'm used to generating X/HTML by hand, which makes the here document in Perl ideal for me. Also, many times a client already existing HTML code that I can use in a script. -- Amer Neely w:www.webmechanic.softouch.on.ca/ Perl | MySQL programming for all data entry forms. Others make web sites. We make web sites work! I am not sure if this is what you are looking for, but Python has a special string with 3 quotes that I believe duplicates part of the functionality of a here document: myHmtlHeader = head attribute = abc titleMy Page/title /head print myHtmlHeader outputs: head attribute=abc titleMy Page/title /head -- http://mail.python.org/mailman/listinfo/python-list
Re: Coming from Perl
TheFlyingDutchman wrote: On Sep 12, 5:30 pm, Amer Neely [EMAIL PROTECTED] wrote: I'm a complete newbie with Python, but have several years experience with Perl in a web environment. A question I have, if someone here is familiar with Perl, does Python have something like Perl's 'here document'? I've just searched and read some postings on generating HTML but they all seem to refer to various template utilities. Is this the only way, or am I missing something? I'm used to generating X/HTML by hand, which makes the here document in Perl ideal for me. Also, many times a client already existing HTML code that I can use in a script. -- Amer Neely w:www.webmechanic.softouch.on.ca/ Perl | MySQL programming for all data entry forms. Others make web sites. We make web sites work! I am not sure if this is what you are looking for, but Python has a special string with 3 quotes that I believe duplicates part of the functionality of a here document: myHmtlHeader = head attribute = abc titleMy Page/title /head print myHtmlHeader outputs: head attribute=abc titleMy Page/title /head Yep, I think that is the way I will have to go. Thanks. -- Amer Neely w: www.webmechanic.softouch.on.ca/ Perl | MySQL programming for all data entry forms. Others make web sites. We make web sites work! -- http://mail.python.org/mailman/listinfo/python-list
RE: Coming from Perl
On Behalf Of Amer Neely I saw that and I guess that is the closest thing. In Perl I can do .. print EndHTML; html body Hello /body /html EndHTML data = dict(title=Python Rocks!, content=pI heart Python/p) template = html head title%(title)s/title /head body %(content)s /body /html print template % data html head titlePython Rocks!/title /head body pI heart Python/p /body /html You might also want to check out string.Template (http://docs.python.org/lib/node40.html), or even move on to one of the many, many templating languages (Mako, Cheetah, Kid, etc.) Regards, Ryan Ginstrom -- http://mail.python.org/mailman/listinfo/python-list
Re: Coming from Perl
Amer Neely [EMAIL PROTECTED] writes: print EndHTML; html body Hello /body /html EndHTML The equivalent in Python would be:: print html body Hello /body /html You can even use Python's standard textwrap module to indent your code properly:: import textwrap def foo(bar): if baz: print textwrap.dedent( html body Hello /body /html ) The 'textwrap.dedent' function strips *common* leading whitespace from all lines in the string, so in the above example the resulting string will be as though the original string were typed flush to the left margin. See 'help(textwrap.dedent)' for what that function does, or read it online URL:http://docs.python.org/lib/module-textwrap. -- \Madness is rare in individuals, but in groups, parties, | `\ nations and ages it is the rule. -- Friedrich Nietzsche | _o__) | Ben Finney -- http://mail.python.org/mailman/listinfo/python-list
