Search Results

Search found 13693 results on 548 pages for 'python metaprogramming'.

Page 46/548 | < Previous Page | 42 43 44 45 46 47 48 49 50 51 52 53  | Next Page >

  • How does polymorphism work in Python?

    - by froadie
    I'm new to Python... and coming from a mostly Java background, if that accounts for anything. I'm trying to understand polymorphism in Python. Maybe the problem is that I'm expecting the concepts I already know to project into Python. But I put together the following test code: class animal(object): "empty animal class" class dog(animal): "empty dog class" myDog = dog() print myDog.__class__ is animal print myDog.__class__ is dog From the polymorphism I'm used to (e.g. java's instanceof), I would expect both of these statements to print true, as an instance of dog is an animal and also is a dog. But my output is: False True What am I missing?

    Read the article

  • How to write a shell in Python

    - by panzi
    I've written a small console application that can perform certain tasks. The user interface is similar to things like version control systems or yum etc. So basically you can think of it as a domain specific language. Now I'd like to write a (bash like) shell that can execute and auto-complete this language and has a command history (so I do not have to load and save the quite large xml files on each command). In a nutshell I want something like ipython but not for executing python code but my own DSL. Are there any libraries that help me doing this? I see that there is a readline and rlcompleter module in python but its documentation seems to indicate that this is only for use with the python shell itself, or did I miss something there?

    Read the article

  • java version of python-dateutil

    - by elhefe
    Python has a very handy package that can parse nearly any unambiguous date and provides helpful error messages on a parse failure, python-dateutil. Comparison to the SimpleDateFormat class is not favorable - AFAICT SimpleDateFormat can only handle one exact date format and the error messages have no granularity. I've looked through the Joda API but it appears Joda is the same way - only one explicit format can be parsed at a time. Is there any package or library that reproduces the python-dateutil behavior? Or am I missing something WRT Joda/SimpleDateFormat?

    Read the article

  • what are the advantages of C# over Python

    - by Matt
    I like Python mostly for the great portability and the ease of coding, but I was wondering, what are some of the advantages that C# has over Python? The reason I ask is that one of my friends runs a private server for an online game (UO), and he offered to make me a dev if I wanted, but the software for the server is all written in C#. I'd love to do this, but I don't really have time to do multiple languages, and I was just after a few more reasons to justify taking C# over Python to myself. I'm doing this all self-taught as a hobby, btw

    Read the article

  • lightweight cryptography toolkit(s) for c++ and python

    - by Joey
    Hi, I'm looking to do some basic encryption of server messages which'd be encrypted with C++ and decrypted using Python serverside. I was wondering if anyone knew if there were good solutions that were simpler or more lightweight than Keyczar. I see that supports both C++ and python, but would using Crypto++ and PyCrypto be simpler for a newbie that just wants to get something up and running for the time being? Or should I use Keyczar for python and Crypto++ for the C++ end? The C++ libraries seem to have dependencies to hundreds of files.

    Read the article

  • Python ValueError: not allowed to raise maximum limit

    - by Ricky Bobby
    I'm using python 2.7.2 on mac os 10.7.3 I'm doing a recursive algorithm in python with more than 50 000 recursion levels. I tried to increase the maximum recursion level to 1 000 000 but my python shell still exit after 18 000 recursion levels. I tried to increase the resources available : import resource resource.setrlimit(resource.RLIMIT_STACK, (2**29,-1)) sys.setrecursionlimit(10**6) and I get this error : Traceback (most recent call last): File "<pyshell#58>", line 1, in <module> resource.setrlimit(resource.RLIMIT_STACK,(2**29,-1)) ValueError: not allowed to raise maximum limit I don't know why I cannot raise the maximum limit ? thanks for your suggestions .

    Read the article

  • Is it possible to install IDLE on Python 2.5 and Ubuntu

    - by broiyan
    Ubuntu Software Center offers versions of IDLE numbered 2.6 and upwards. If I have to use Python 2.5 (because of Google App Engine compatibility), will it be possible to still use IDLE? I am of course assuming that the there is some necessity for the IDLE version number to be the same as the Python version number. Presently, my invocations of IDLE fail because of _tkinter not being found. Likewise it is not found when I try to do an import _tkinter interactively. I then proceeded to install Tcl and Tk and python-tk and one of the IDLE versions being offered (none were labelled 2.5) but _tkinter still does not get imported.

    Read the article

  • CentOS: revert python version back to original

    - by NP
    Hi all, I installed python 2.6 using the instructions here on CentOS 5.4. However I realized it was a bad move and I need to revert back to 2.4, which was there originally. Can anyone guide me on how to undo what I did here? In particular, I am not sure how to undo this: Configure ld to find your shared libs: $ cat /etc/ld.so.conf.d/opt-python2.5.conf /opt/python2.5/lib (hit enter) (hit ctrl-d to return to shell) $ ldconfig I tried removing the alias and the symlink and even re-aliasing python to /usr/bin/python, but when I try to install an RPM i get this error: error: Failed dependencies: libpython2.4.so.1.0 is needed by ... Thanks in advance.

    Read the article

  • Python - converting wide-char strings from a binary file to Python unicode strings...

    - by Mikesname
    It's been a long day and I'm a bit stumped. I'm reading a binary file that contains lots of wide-char strings and I want to dump these out as Python unicode strings. (To unpack the non-string data I'm using the struct module, but I don't how to do the same with the strings.) For example, reading the word "Series": myfile = open("test.lei", "rb") myfile.seek(44) data = myfile.read(12) # data is now 'S\x00e\x00r\x00i\x00e\x00s\x00' How can I encode that raw wide-char data as a Python string? Edit: I'm using Python 2.6

    Read the article

  • An simple Python extension in C

    - by celil
    I am trying to create a simple python extension module. I compiled the following code into a transit.so dynamic module #include <python2.6/Python.h> static PyObject* _print(PyObject* self, PyObject* args) { return Py_BuildValue("i", 10); } static PyMethodDef TransitMethods[] = { {"print", _print, METH_VARARGS, ""}, {NULL, NULL, 0, NULL} }; PyMODINIT_FUNC inittransit(void) { Py_InitModule("transit", TransitMethods); } However, trying to call this from python import transit transit.print() I obtain an error message File "test.py", line 2 transit.print() ^ SyntaxError: invalid syntax What's wrong with my code?

    Read the article

  • A simple Python extension in C

    - by celil
    I am trying to create a simple python extension module. I compiled the following code into a transit.so dynamic module #include <python2.6/Python.h> static PyObject* _print(PyObject* self, PyObject* args) { return Py_BuildValue("i", 10); } static PyMethodDef TransitMethods[] = { {"print", _print, METH_VARARGS, ""}, {NULL, NULL, 0, NULL} }; PyMODINIT_FUNC inittransit(void) { Py_InitModule("transit", TransitMethods); } However, trying to call this from python import transit transit.print() I obtain an error message File "test.py", line 2 transit.print() ^ SyntaxError: invalid syntax What's wrong with my code?

    Read the article

  • Python - which multi platform GUI framework to use?

    - by Iacopo
    Hi, I've written a Python GUI application and made it run on Linux, Windows and Mac. The framework I'm using is PyGtk. The final result is not really good: the application looks horrible on Mac, and it is not really 'native' neither on Windows. Furthermore on Mac the windows' behavior is sometimes wrong, with modal dialogs appearing below the main windows. I've explored other frameworks and I've found that a porting may be really hard: PyQt it is huge, difficult to install and to distribute under Mac; PyGui is poor: I need tables and tree views at least; wxPython state explicitly that you have to use a custom python build for Mac Tkinter: didn't check it, only have the impression that it is obsolete I know this question may appear similar to http://stackoverflow.com/questions/394039/which-python-gui-framework but in that thread the portability issue is not really taken in account. Windows and Mac are a must, since most of my user have that systems. Can you also suggest some books?

    Read the article

  • How to set parameters in Python zlib module

    - by fagricipni
    I want to write a Python program that makes PNG files. My big problem is with generating the CRC and the data in the IDAT chunk. Python 2.6.4 does have a zlib module, but there are extra settings needed. The PNG specification REQUIRES the IDAT data to be compressed with zlib's deflate method with a window size of 32768 bytes, but I can't find how to set those parameters in the Python zlib module. As for the CRC for each chunk, the zlib module documentation indicates that it contains a CRC function. I believe that calling that CRC function as crc32(data,-1) will generate the CRC that I need, though if necessary I can translate the C code given in the PNG specification. Note that I can generate the rest of the PNG file and the data that is to be compressed for the IDAT chunk, I just don't know how to properly compress the image data for the IDAT chunk after implementing the initial filtering step.

    Read the article

  • call multiple c++ functions in python using threads

    - by wiso
    Suppose I have a C(++) function taking an integer, and it is bound to (C)python with python api, so I can call it from python: import c_module c_module.f(10) now, I want to parallelize it. The problem is: how does the GIL work in this case? Suppose I have a queue of numbers to be processed, and some workers (threading.Thread) working in parallel, each of them calling c_module.f(number) where number is taken from a queue. The difference with the usual case, when GIL lock the interpreter, is that now you don't need the interpreter to evaluate c_module.f because it is compiled. So the question is: in this case the processing is really parallel?

    Read the article

  • Python comparing string against several regular expressions

    - by maerics
    I'm pretty experienced with Perl and Ruby but new to Python so I'm hoping someone can show me the Pythonic way to accomplish the following task. I want to compare several lines against multiple regular expressions and retrieve the matching group. In Ruby it would be something like this: STDIN.each_line do |line| case line when /^A:(.*?)$/ then puts "FOO: #{$1}" when /^B:(.*?)$/ then puts "BAR: #{$1}" # when ... else puts "NO MATCH: #{line}" end end My attempts in Python are turning out pretty ugly because the matching group is returned from a call to match/search on a regular expression and Python has no assignment in conditionals or switch statements. What's the Pythonic way to do (or think!) about this problem?

    Read the article

  • Error loading SQL_VARIANT data type using Python

    - by Brett D
    I am using Python and SQLAlchemy to query a database that I did not create. I have run into a problem querying a table that contains the SQL_VARIANT data type. I get the error: sqlalchemy.exc.DBAPIError: (Error) ('ODBC data type -150 is not supported. Cannot read column Value.', 'HY000') I confirmed with the database creator that the "Value" column is of type SQL_VARIANT. Does anyone know a way to load this data type using Python? I am currently using mssql with pyodbc. Thank you for any help you can offer! Versions: Python 2.7, SQLAlchemy 0.7.8

    Read the article

  • Does Python work in larger teams?

    - by Kugel
    I read this post last night and it got me thinking. I like python and "batteries", pypi and such. But I've only done python solo. Never tried it in a team. Are the points that Ted mentions valid? If they are how do teams cope with them? Does Python work in teams or even large teams? Or it kills productivity? I personally see the problems he mentions when I come back to my old code. Even when working with other modules sometimes I need to peek inside. I would like to hear people with experience on this.

    Read the article

  • Determine calling executable in Python

    - by Brian Rosner
    I am trying to find the best way of re-invoking a Python script within itself. Currently it is working like http://github.com/benoitc/gunicorn/blob/master/gunicorn/arbiter.py#L285. The START_CTX is created at http://github.com/benoitc/gunicorn/blob/master/gunicorn/arbiter.py#L82-86. The code is relying on sys.argv[0] as the "caller". However, this fails in cases where it is invoked with: python script.py ... This case does work: python ./script.py ... because the code uses os.chdir before running os.execlp. I did notice os.environ["_"], but I am not sure how reliable that would be. Another possible case is to check if sys.argv[0] is not on PATH and is not executable and use sys.executable when calling os.execlp. Any thoughts on a better approach solving this issue?

    Read the article

  • word ladder in python

    - by user365523
    I'm trying to create a word ladder program in python. I'd like to generate words that are similar to a given word. In c++ or java, I would go through each valid index in the original string, and replace it with each letter in the english alphabet, and see if the result is a valid word. for example (pseudocode) for (int i = 0; i < word.length(); i++) { for (every character c in the alphabet) { change the letter of word at index i to be c. if the result is a valid word, store it in a list of similar words } } . However, this doesn't seem like a very "python" way of doing things. How would I approach this problem in python?

    Read the article

  • construct graph from python set type.

    - by Vincent
    The sort question, is the an off the self function to make a graph from a set of python sets? The longer: I have several python set types. They each overlap or some are sub sets of others. I would like to make a graph (as in nodes and edges) with the edges weighted by common intersection of the sets. There are several graphing packages for python. (NetworkX, igraph,...) I am not familiar with the use of any of them. Will any of them make a graph directly from a list of sets ie, MakeGraphfromSets(alistofsets) If not do you know of an example of how to take the list of sets to define the edges. It actually looks like it might be straight forward but an example is always good to have.

    Read the article

  • What is a flexible, hybrid python collection object?

    - by Naveen
    As a way to get used to python, I am trying to translate some of my code to python from Autohotkey_L. I am immediately running into tons of choices for collection objects. Can you help me figure out a built in type or a 3rd party contributed type that has as much as possible, the functionality of the AutoHotkey_L object type and its methods. AutoHotkey_L Objects have features of a python dict, list, and a class instance. I understand that there are tradeoffs for space and speed, but I am just interested in functionality rather than optimization issues.

    Read the article

  • How to tell process id within Python

    - by R S
    Hey, I am working with a cluster system over linux (www.mosix.org) that allows me to run jobs and have the system run them on different computers. Jobs are run like so: mosrun ls & This will naturally create the process and run it on the background, returning the process id, like so: [1] 29199 Later it will return. I am writing a Python infrastructure that would run jobs and control them. For that I want to run jobs using the mosrun program as above, and save the process ID of the spawned process (29199 in this case). This naturally cannot be done using os.system or commands.getoutput, as the printed ID is not what the process prints to output... Any clues? Edit: Since the python script is only meant to initially run the script, the scripts need to run longer than the python shell. I guess it means the mosrun process cannot be the script's "son process". Any suggestions? Thanks

    Read the article

  • GWT on Python App Engine

    - by Koran
    Hi, I have a python app engine code (matured backend) - and we are now planning to have a front end for that code. I was wondering whether it is possible to implement GWT as the front end. Even though Alex Martelli in this post [1] mentions it is not possible, a comment to that post suggests that it is indeed possible using rpc over json for GWT. I was unable to understand how this is possible. In app.yaml file, we have to specify the language to be python, right? In that case, how can it compile GWT based on JAVA? Are there any examples on anyone doing that? Can someone help me out? It would be extremely helpful. [1]: http://stackoverflow.com/questions/1085898/choosing-java-vs-python-on-google-app-engine/1087878#1087878 link

    Read the article

  • Connecting to Google app email servers in Python to send from an alias

    - by user575228
    I'm looking to send many emails via Python and would like to connect to Google's email servers to send it from my company email address (it's for work). I've got working code for sending the email through the old company email ([email protected]) which is our login, but can't figure out how to send it through the alias ([email protected]) we use frequently. Long story short, logging in with my regular Google Apps account won't do and I need to sign in with an alias (nickname) instead. Alternatively, I can sign with the regular account ([email protected]) but send via a different email ([email protected]). Working in python and pretty new to programming, but am a good listener! (It's like this question: Google Apps - Send email from a nickname but in Python).

    Read the article

  • advanced python autovivification

    - by Zhang18
    This question is about implementing the full PERL autovivification in python. I know similary questions were asked before and so far the best answre is http://stackoverflow.com/questions/635483/what-is-the-best-way-to-implement-nested-dictionaries-in-python/652284#652284. However, I'm looking to do this: a['x']['y'].append('z') without declaring a['x']['y'] = [] first, or rather, not declaring a['x'] = {} either. I know dict and list classes sorta don't mix so this is hard, but I'm interested in seeing if someone has an ingenius solution probably involving creating an inherited class from dict but defined a new append method on it? I also know this might throw off some python purists who will ask me to stick with Perl. But even just for a challenge, I'd like to see something. thx!

    Read the article

< Previous Page | 42 43 44 45 46 47 48 49 50 51 52 53  | Next Page >