In Python, one bug that often bites me is this:
(example A)
aList = [1,2,3]
for i in aList:
i += 1
print aList
--> [1,2,3]
This goes against my intuition, which is that aList == [2,3,4], probably
because so much in Python is passed by reference and not by value. Of
course I can always use ran
Hi,
This code works, but I don't like it much:
def authenticateAuthor(author, password):
authorxml = 'author.xml'
path = os.path.join(xml, authorxml)
try: if not os.path.exists(path):
authorfile = False
else:
authorfile = True
tree = E.ElementTree(file=path
On 11 Feb 2005, [EMAIL PROTECTED] wrote:
>> FOR THE LOVE OF MIKE can someone tell me even one reason why this
>> isn't a misfeature?!?!
> Its the only sane way to implement default arguments. The whole
> point of function definitions is that they provide a single concise
> interface. The funct
> >way we ASP.NET at my company, and I'm having some trouble finding a good
> >way to organize all the code.
>
> My take on doing that in Python:
>
> Organize things into modules. Especially with an eye to potential reuse.
> Look at the module index in the docs to see how most of the "standard"
>
On Fri, 11 Feb 2005, Lobster wrote:
> The tutorials I am accessing with Firefox and there seems to be a
> conflict in which the Idle editor is trying to (or reported as accessing
> the Net but does not (according to the literature and warning)
Hello!
IDLE does use network connections to talk t
At 01:38 PM 2/11/2005, Kent Johnson wrote:
Mark Brown wrote:
Hi,
I'm a newbie and was wondering which of these IF conditions is better
structure:
1. if not os.path.exists('filename'):
I prefer the above.
2. if os.path.exists('filename') == False:
They both work so if one preferred over the o
Bob Gailer wrote:
At 01:38 PM 2/11/2005, Kent Johnson wrote:
Note that in Python in general, 'not x' and 'x == False' are not
equivalent; 'not x' will be true for many more values than just False.
For example
not 0
not 0.0
not []
not {}
are all True.
Oops. 0 and 0.0 do == False.
Uh, right. Than
At 01:38 PM 2/11/2005, Kent Johnson wrote:
Mark Brown wrote:
Hi,
I'm a newbie and was wondering which of these IF conditions is better
structure:
1. if not os.path.exists('filename'):
I prefer the above.
2. if os.path.exists('filename') == False:
They both work so if one preferred over the o
Mark Brown wrote:
Hi,
I'm a newbie and was wondering which of these IF conditions is better
structure:
1. if not os.path.exists('filename'):
I prefer the above.
2. if os.path.exists('filename') == False:
They both work so if one preferred over the other?
Note that in Python in general, 'not
Mark Brown wrote:
I'm a newbie and was wondering which of these IF conditions is better
structure:
1. if not os.path.exists('filename'):
2. if os.path.exists('filename') == False:
I prefer the "if not" variety.
Yours,
Andrei
___
Tutor maillist -
At 10:39 AM 2/11/2005, Ryan Davis wrote:
I'm
starting to make a code-generation suite in python, customized to the way
we ASP.NET at my company, and I'm having some trouble finding a good way
to organize all the code.
My take on doing that in Python:
Organize things into modules. Especially wit
Hi
Just started with Idle and Python :-)
The tutorials I am accessing with Firefox
and there seems to be a conflict in which the
Idle editor is trying to (or reported as accessing the Net
but does not (according to the literature and warning)
More seriously I can not run Idle and Firefox together
At 08:52 AM 2/11/2005, Mark Brown wrote:
Hi,
I'm a newbie and was wondering which of these IF conditions is better
structure:
if not os.path.exists('filename'):
IMHO the above is preferable to the below. It is much more
"intuitive".
if os.path.exists('filename') == False:
Bob Gailer
mailto:[EM
> I don't know any good on-line resources for learning SQL
I like
http://www.sqlcourse.com/
Its got a live SQL prompt so you can practice with their database
and see the results. It seems fairly clearly written too.
Caveat: I'#ve only gone through a few of the pages to check
it out, I haven'
On Fri, 11 Feb 2005, Smith, Jeff wrote:
> I'm sorry to both with such a simple question but I've looked in the
> normal places and don't see the quick and dirty answer I know must
> exist.
>
> I want to write a simple line selection filter that could be used like:
>
> filter < file
>
> I get the
I also recommend learning SQL. It is not very hard to learn, and
sometimes it may be advantageous to do data manipulation directly in the
database, rather than with Python. As far as databases go, I would
recommend Firebird, as I have found that it has a good number of
features, is free, and
Alan Gauld wrote:
(And to pick up on someone else's question this is why you should
put in a __del__ to tidy up the Node list when Body is destructed
- otherwise you get circular references which can cause memory
leaks by confusing the garbage collector!
CPython has been able to GC cycles since ver
> I'm a newbie and was wondering which of these IF conditions is
better structure:
> 1.. if not os.path.exists('filename'):
> 2.. if os.path.exists('filename') == False:
Which one reads easiest?
I'd say the first one personally. But both are OK.
Alan G.
_
> My Example Body
> Node List
>Node the first
>Node the second
>
> Is there any way to make methods of the Node class access attributes
> of `parents' of instances? I would like a Node instance such as Node
> the first above to be aware just what it is a node of and what its
> s
> I have been reading code written before me (mind you it's C++) and
the
> authors seemed to follow what ever style they wished to that day.
And that's C++ style, it has no single standard approach...
> that's the nature of the beast.
How very true.
Alan G.
> Can and if you can how do you set a variable as a constant?
Only by resorting to tricks involving classes and properties.
There is a cookbook recipe if I recall correctly.
Vanilla Python doesn't have the concept of constants other
than as a naming convention (all uppercase). Its part of the
> In Perl I would do:
>
> while (<>)
> {
> print if line meets selection criteria;
> }
You may want to check out the fileinput module.
It takes care of multiple files being passed as input and such like
too.
> for line in sys.stdin:
> if line meets selection criteria:
> print line
>for line
>
> FOR THE LOVE OF MIKE can someone tell me even one reason why this
> isn't a misfeature?!?!
>
:-)
Its the only sane way to implement default arguments. The whole
point of function definitions is that they provide a single concise
interface. The function should return the same result each
> I'm looking to create a prog that will store disparate bits of info
> all linked together, i.e. address details for a person, transaction
> records, specific themes, and the ability to search by certain
> criteria, so I'm pretty sure I want a database.
Sounds a lot like it!
> Can anyone recomme
I'm starting to make a code-generation suite in python, customized
to the way we ASP.NET at my company, and I'm having some trouble finding a good
way to organize all the code. I
keep writing it, but it feels more and more spaghetti-ish
every day.
I'm going to look at the other stuff i
Brian van den Broek wrote:
Alan Gauld said unto the world upon 2005-02-10 02:58:
Pseudo code:
class Body:
def __init__(self,content):
self.contents = contents
self.nodes = []
def parse(self):
for line in self.contents:
Brian van den Broek wrote:
Alan Gauld said unto the world upon 2005-02-10 02:58:
Pseudo code:
class Body:
def __init__(self,content):
self.contents = contents
self.nodes = []
def parse(self):
for line in self.contents:
Alan Gauld said unto the world upon 2005-02-10 02:58:
Pseudo code:
class Body:
def __init__(self,content):
self.contents = contents
self.nodes = []
def parse(self):
for line in self.contents:
if line == NodeStartTag:
Mark Brown wrote:
Hi,
I'm a newbie and was wondering which of these IF conditions is better
structure:
if not os.path.exists('filename'):
if os.path.exists('filename') == False:
My preference would be the first (if not os.path.exists).
os.path.exists returns a boolean (I
Hi,
I'm a newbie and was wondering which of these IF conditions is better
structure:
if not os.path.exists('filename'):
if os.path.exists('filename') == False:
They both work so if one preferred over the other?
Thanks
Mark Brown
___
Tutor ma
Thanks that's what I thought.
Wasn't 100% sure that is what prompted me to ask the question in here.
As for the CAPS thing for constants, I generally try and practice (to the
best of my knowledge) proper programming consepts/styles/standards. However
I have been reading code written before me
Jeff,
On Fri, 11 Feb 2005 10:03:30 -0500, Jeffrey Maitland <[EMAIL PROTECTED]> wrote:
>
> Hello all,
>
> I am drawing a blank right now and can't seem to find anything on it and I
> am sure this issue has been addressed before, so here is the question.
>
> Can and if you can how do you set a va
Good catch Bill,
I was using assoc and ftype to allow me to run my filter.py directly as
a command and using:
filter < file
Unfortunately, Windows doesn't handle this properly and I had to do
C:\Python24\python filter.py < file
To get it to work.
Thanks,
Jeff
P.S. In retrospect, I've had the
Hello all,
I am drawing a blank right now and can't seem to find anything on it and I
am sure this issue has been addressed before, so here is the question.
Can and if you can how do you set a variable as a constant?
Example of what I mean: (this is loose and not python since variable type
On Fri, 11 Feb 2005 09:28:35 -0500, Smith, Jeff <[EMAIL PROTECTED]> wrote:
> I'm sorry to both with such a simple question but I've looked in the
> normal places and don't see the quick and dirty answer I know must
> exist.
>
No worries; that's what this list is for.
> I want to write a simple l
I'm sorry to both with such a simple question but I've looked in the
normal places and don't see the quick and dirty answer I know must
exist.
I want to write a simple line selection filter that could be used like:
filter < file
In Perl I would do:
while (<>)
{
print if line meets selec
Kent Johnson wrote:
I don't know any good on-line resources for learning SQL
The Wikipedia entry for SQL has links to quite a few tutorials:
http://en.wikipedia.org/wiki/Sql
Kent
___
Tutor maillist - Tutor@python.org
http://mail.python.org/mailman/listi
Brian van den Broek wrote:
At first, I ended up with every single node being a copy of the first
one processed. A bit of weeping later, I realized that this is from the
feature [?] of Python that default arguments are evaluated just once.
(Note the comment added above.)
FOR THE LOVE OF MIKE ca
Kent Johnson wrote:
SQL is a standardized language for giving commands to databases. Most
(all?) industrial-strength databases use SQL as their command language.
(DB-API is actually a wrapper around SQL - it standardizes the API to
issue a SQL command and read the results.)
SQL is kind of a str
I would recommend KirbyBase as a quick starter - it's nice and simple,
and outputs text files, so you can always check things manually.
http://www.netpromi.com/kirbybase.html
Matt
___
Tutor maillist - Tutor@python.org
http://mail.python.org/mailman/
Liam Clarke wrote:
Hi,
I'm looking to create a prog that will store disparate bits of info
all linked together, i.e. address details for a person, transaction
records, specific themes, and the ability to search by certain
criteria, so I'm pretty sure I want a database.
Can anyone recommend a usef
Alan Gauld said unto the world upon 2005-02-10 02:58:
class Node:
def __init__(self,lines=[]): # here's the zowie BvdB
self.lines = lines
def append(self,item):
self.lines.append(item)
def parse(self):
#
42 matches
Mail list logo
