[Tutor] Variables in workspace
Hello I am working with python interactively using IDLE. Since starting, I defined some variables: s='string' a=1 b=[1,2] c=1.02 and so on. Now, I want to know which variables are in my workspace. That is, is there a command similar to who in MATLAB ? I want to call who and get the output: s a b c (a listing of all the variables I defined in the session) Now, is there a way to clear some or all the variables in that list ? Thanks Eli ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Variables in workspace
Eli Brosh wrote: I am working with python interactively using IDLE. Since starting, I defined some variables: Now, I want to know which variables are in my workspace. RESTART dir() ['__builtins__', '__doc__', '__name__'] s='string' a=1 dir() ['__builtins__', '__doc__', '__name__', 'a', 's'] Now, is there a way to clear some or all the variables in that list ? del a del s dir() ['__builtins__', '__doc__', '__name__'] To clear all you can Restart Shell from the menu. Kent ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Variables in workspace
Eli Brosh wrote: Hello I am working with python interactively using IDLE. Since starting, I defined some variables: s='string' a=1 b=[1,2] c=1.02 and so on. Now, I want to know which variables are in my workspace. That is, is there a command similar to who in MATLAB ? I want to call who and get the output: s a b c (a listing of all the variables I defined in the session) Start IDLE, then enter dir(). That will give you the names already in the workspace. Then assign your variables and enter dir() again. Now, is there a way to clear some or all the variables in that list ? Clear? Do you mean set to None or delete them? The del statement is the way to delete variables. Since dir() gives you their names one needs use eval. for varName in dir(): eval 'del ' + varName Of course that is overkill as it will delete __builtins__ etc, so you want to screen out all the names that you see in the initial dir() call. ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] slice lists and slicing syntax questions
On 10/12/07, [EMAIL PROTECTED] [EMAIL PROTECTED] wrote: I have been using Python for years now, in all kinds of environments, but example: x is vector of length 5, with value a,b,c,d,e , then: x[3,1,1,1,3,2] # gives [d, b, b, b, d, c] What is the python equivalent? a. Am I understanding the situation correctly? When you call [] on an object, it calls __getitem__The definition for getitem is __getitem__(self,key), where key can be an integer or a slice object. Slice objects are either a range or a range+step. You've got the right picture b. Why was this particular way of doing slices chosen? Dunno. I'll leave this to the language historians. I will say a differently implemented slice object interface would lend itself to novel types of slicing, like you're talking about. If, for instance, the slice object would return an iterator of indicies, you could add this case to the indexable objects. However, the way it currently is, I don't see that being possible. Also, the way it currently is, I don't see it working well with all the code that implements __getitem__ as it's currently written even if slice was implemented. c. What is the best solution for masking vectors? I'm with a decorator, you can get to at least x(4,3,3,3,2,1) returning the type of list you want. At the same time, I'm not sure you're going to be able to override the __getitem__ prototype without some serious pain.I've never tried to change the function/method signature with a decorator, but I'm pretty sure its possible at least for the non-builtin attributes. You may want to try to write a PEP for python 3000. So much is being changed with that, you may get it in. --Michael -- Michael Langford Phone: 404-386-0495 Consulting: http://www.TierOneDesign.com/ ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] slice lists and slicing syntax questions
Michael Langford wrote: When you call [] on an object, it calls __getitem__The definition for getitem is __getitem__(self,key), where key can be an integer or a slice object. Or a tuple of integers/slices. You may want to try to write a PEP for python 3000. So much is being changed with that, you may get it in. The deadline for PEPs for Python 3 has long passed - it was in April IIRC. Kent ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Variables in workspace
bob gailer wrote: The del statement is the way to delete variables. Since dir() gives you their names one needs use eval. for varName in dir(): eval 'del ' + varName I think del globals()[varName] would work. Kent ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Variables in workspace
Kent Johnson wrote: bob gailer wrote: The del statement is the way to delete variables. Since dir() gives you their names one needs use eval. for varName in dir(): eval 'del ' + varName I think del globals()[varName] would work. Yep. That was nagging a corner of my brain, but not surfacing. ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Variables in workspace
Eli Brosh [EMAIL PROTECTED] wrote
Now, I want to know which variables are in my workspace.
Try dir()
That should give you the names in the current namespace.
You will see some names you didn't define too.
dir()is a really helpful command when you want to see whats possible.
dir('')
Will list all the methods of a string for example.
import math
dir(math)
will list all the math functions and constants.
HTH,
--
Alan Gauld
Author of the Learn to Program web site
http://www.freenetpages.co.uk/hp/alan.gauld
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[Tutor] upgrading Python
I wish to upgrade Python from the [Vers.] 2.3.4 that came packaged with my Mandrake 10.1 Linux OS to the current 2.5.1. The 'hash/bang' line of my python scripts is #!/usr/bin/python. There are two files, both executables, in my /usr/bin directory; they are 1)python, and 2)python2.3. I just simply don't know what to do next!? The advise I can google to is typically overly generous, full of contradictions (sometime within the same post...Well you can do this, but if you wanna do that instead...). Well, I don't know why I want to do this, or do that instead. I just want to know where to put my new version of python, and when I unzip/configure/and so on..., will I end up with: 1)an application that will pick up seamlessly and run my apps? 2)will pythontutor still be available? 3)will I have an upgraded accessible package of modules? 4)will I need to modify the hash/bang line? 5)when I type 'python' on a command line, how will I access the new 2.5.1 rather than the older version? i.e., where do I go to modify the results of that request? Oh, and could I-as I understand (to a limited degree) Linux- install the entire package within my home directory, following the principle that I am a user without admin privileges, and then change the hash/bang line to redirect to my 'embedded' version, and thus be running 2.5.1 within my own little world? And if I did so, the same questions persist. If I asked for a module, would I get the one from my 2.5.1, or the module that exists in the older 2.3.4? And when I entered 'python' from a command line (to access the interpreter) how would I get my 2.5.1 version, rather than the older 2.3.4. It's just amazing, the array of niggling little questions that no one thinks about, but that create unmountable stumbling blocks once they pop up in the middle of your path, isn't it!? But, they are enough to completely stop me in my tracks, and they are the nitty-gritty questions that no one seems to think important enough to address and clarify. Thanks, folks. ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] upgrading Python
Hi there, I'm not familiar with Mandrake, but I use Ubuntu Linux and my package manager does updates for me. It looks like Madrake has a package manager called urpmi according to Wikipedia - have you tried using that to install a new RPM package for Python 2.5.1 or simply trying to have it automatically update for you? If you have some other package manager there may be a different way to do it though - if you had apt-get or Synaptic I could walk you through it that way. Anyway, once you do have it installed, I believe that /usr/bin/python just has the basic stuff and references everything else in the other executable script, so you shouldn't have to change the #! line ever ever. I hope something I said helps with Q45! Dave On 10/13/07, LandSurveyor [EMAIL PROTECTED] wrote: I wish to upgrade Python from the [Vers.] 2.3.4 that came packaged with my Mandrake 10.1 Linux OS to the current 2.5.1. The 'hash/bang' line of my python scripts is #!/usr/bin/python. There are two files, both executables, in my /usr/bin directory; they are 1)python, and 2)python2.3. I just simply don't know what to do next!? The advise I can google to is typically overly generous, full of contradictions (sometime within the same post...Well you can do this, but if you wanna do that instead...). Well, I don't know why I want to do this, or do that instead. I just want to know where to put my new version of python, and when I unzip/configure/and so on..., will I end up with: 1)an application that will pick up seamlessly and run my apps? 2)will pythontutor still be available? 3)will I have an upgraded accessible package of modules? 4)will I need to modify the hash/bang line? 5)when I type 'python' on a command line, how will I access the new 2.5.1rather than the older version? i.e., where do I go to modify the results of that request? Oh, and could I-as I understand (to a limited degree) Linux- install the entire package within my home directory, following the principle that I am a user without admin privileges, and then change the hash/bang line to redirect to my 'embedded' version, and thus be running 2.5.1 within my own little world? And if I did so, the same questions persist. If I asked for a module, would I get the one from my 2.5.1, or the module that exists in the older 2.3.4? And when I entered 'python' from a command line (to access the interpreter) how would I get my 2.5.1 version, rather than the older 2.3.4. It's just amazing, the array of niggling little questions that no one thinks about, but that create unmountable stumbling blocks once they pop up in the middle of your path, isn't it!? But, they are enough to completely stop me in my tracks, and they are the nitty-gritty questions that no one seems to think important enough to address and clarify. Thanks, folks. ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] slice lists and slicing syntax questions
On Sat, Oct 13, 2007 at 10:32:39AM -0400, Michael Langford wrote: On 10/12/07, [EMAIL PROTECTED] [EMAIL PROTECTED] wrote: I have been using Python for years now, in all kinds of environments, but example: x is vector of length 5, with value a,b,c,d,e , then: x[3,1,1,1,3,2] # gives [d, b, b, b, d, c] What is the python equivalent? a. Am I understanding the situation correctly? When you call [] on an object, it calls __getitem__The definition for getitem is __getitem__(self,key), where key can be an integer or a slice object. Slice objects are either a range or a range+step. You've got the right picture __getitem__() suggests a Pythonic solution: subclass list and override __getitem__(): class subscriptlist(list): def __getitem__(self, subscripts): #print 'type(subscripts):', type(subscripts) if (isinstance(subscripts, tuple) or isinstance(subscripts, list)): vals = [] for subscript in subscripts: vals.append(list.__getitem__(self, subscript)) return vals else: val = list.__getitem__(self, subscripts) return val def test(): a = range(10) b = [x * 5 for x in a] c = subscriptlist(b) d = c[2,5,6,8] print 'd:', d e = c[2] print 'e:', e test() Which prints out: d: [10, 25, 30, 40] e: 10 Was that what you wanted? Notice that c[2,5,6,8] results in passing a tuple to __getitem__, because it is the comma that marks a literal representation of a tuple. Dave -- Dave Kuhlman http://www.rexx.com/~dkuhlman ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Variables in workspace
On Sat, Oct 13, 2007 at 11:04:05AM +0200, Eli Brosh wrote: Hello I am working with python interactively using IDLE. Since starting, I defined some variables: s='string' a=1 b=[1,2] c=1.02 and so on. Now, I want to know which variables are in my workspace. That is, is there a command similar to who in MATLAB ? I want to call who and get the output: s a b c (a listing of all the variables I defined in the session) Now, is there a way to clear some or all the variables in that list ? What is your purpose? What is your use case? Usually, when this question or its spawn come up on this list, the answer (and the right one, I think) is: Do not use separate variables, use keys in a dictionary. And, you might think: But that's not what I asked for. However, as your mother might say: That's what's good for you. Also, remember, in Python, global variables are just entries in the dictionary returned by globals(), anyway. Dave -- Dave Kuhlman http://www.rexx.com/~dkuhlman ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] upgrading Python
Greetings, On my system I can have several python versions installed because they install as python2.3, python2.4, etc. $ which python /usr/bin/python $ ls -l /usr/bin/python ... /usr/bin/python - python2.4 Here, we can see that python is just a link to /usr/bin/python2.4 So, I can install python 2.5, and simply change the link so when I enter python at the prompt, it will start python2.5. $ man ln ln [OPTION]... [-T] TARGET LINK_NAME (1st form) So, after installing python 2.5, change to /usr/bin, remove /usr/bin/python $ cd /usr/bin $ rm python And now make a new link to python2.5 (you may have to be root!): # ln -s /usr/bin/python2.5 python If I'm not mistaken, the library files, and so forth are stored in different directories, so installing a new version, won't corrupt an older version. /lib/python2.4/site-packages See how python 2.4 is in the python2.4 directory? If, for some reason, you want the other version, just start it with the absolute pathname: $ /usr/bin/python2.3 I hope this is helpful? I don't use Mandrake, so I'm unfamiliar with its package manager, or how to do upgrades for it. The above are generic *nix commands that should work with any distro. apt-get and Synaptic rock! =) -- b h a a l u u at g m a i l dot c o m http://www.geocities.com/ek.bhaaluu/index.html On 10/13/07, LandSurveyor [EMAIL PROTECTED] wrote: I wish to upgrade Python from the [Vers.] 2.3.4 that came packaged with my Mandrake 10.1 Linux OS to the current 2.5.1. The 'hash/bang' line of my python scripts is #!/usr/bin/python. There are two files, both executables, in my /usr/bin directory; they are 1)python, and 2)python2.3. I just simply don't know what to do next!? The advise I can google to is typically overly generous, full of contradictions (sometime within the same post...Well you can do this, but if you wanna do that instead...). Well, I don't know why I want to do this, or do that instead. I just want to know where to put my new version of python, and when I unzip/configure/and so on..., will I end up with: 1)an application that will pick up seamlessly and run my apps? 2)will pythontutor still be available? 3)will I have an upgraded accessible package of modules? 4)will I need to modify the hash/bang line? 5)when I type 'python' on a command line, how will I access the new 2.5.1 rather than the older version? i.e., where do I go to modify the results of that request? Oh, and could I-as I understand (to a limited degree) Linux- install the entire package within my home directory, following the principle that I am a user without admin privileges, and then change the hash/bang line to redirect to my 'embedded' version, and thus be running 2.5.1 within my own little world? And if I did so, the same questions persist. If I asked for a module, would I get the one from my 2.5.1, or the module that exists in the older 2.3.4? And when I entered 'python' from a command line (to access the interpreter) how would I get my 2.5.1 version, rather than the older 2.3.4. It's just amazing, the array of niggling little questions that no one thinks about, but that create unmountable stumbling blocks once they pop up in the middle of your path, isn't it!? But, they are enough to completely stop me in my tracks, and they are the nitty-gritty questions that no one seems to think important enough to address and clarify. Thanks, folks. ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
[Tutor] File upload from python shell
Hello! How can I upload a file from python? If it is a form to fill with values it's simple: urlopen(http://site.com/action?key1=value1;key2=value2;) and I get the form filled. What about uploading a file programmaticaly? Thank you Paulino ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
[Tutor] [tutor] Formbuffer question in PIL
Hello all, I need some help in using formbuffer function in PIL. Does anybody have sample program related to this ? thanks, -- Varsha ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] [tutor] Formbuffer question in PIL
oops.. i wanted to ask about frombuffer which is in image library of PIL. I read the documentation but wanted a small sample program to understand its function... On 10/13/07, Varsha Purohit [EMAIL PROTECTED] wrote: Hello all, I need some help in using formbuffer function in PIL. Does anybody have sample program related to this ? thanks, -- Varsha -- Varsha Purohit, Graduate Student, ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
