Search Results

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

Page 64/548 | < Previous Page | 60 61 62 63 64 65 66 67 68 69 70 71  | Next Page >

  • writing a fast parser in python

    - by panzi
    I've written a hands-on recursive pure python parser for a some file format (ARFF) we use in one lecture. Now running my exercise submission is awfully slow. Turns out by far the most time is spent in my parser. It's consuming a lot of CPU time, the HD is not the bottleneck. I wonder what performant ways are there to write a parser in python? I'd rather not rewrite it in C. I tried to use jython, but that decreased performance a lot! The files I parse are partially huge ( 150 MB) with very long lines. My current parser only needs a look-ahead of one character. I'd post the source here but I don't know if that's such a good idea. After all the submission deadline has not jet ended. But then, the focus in this exercise is not the parser. You can choose whatever language you want to use and there already is a parser for Java.

    Read the article

  • Detecting Infinite recursion in Python or dynamic languages

    - by drozzy
    Recently I tried compiling program something like this with GCC: int f(int i){ if(i<0){ return 0;} return f(i-1); and it ran just fine. When I inspected the stack frames the compiler optimized the program to use only one frame, by just jumping back to the beginning of the function and only replacing the arguments to f. And - the compiler wasn't even running in optimized mode. Now, when I try the same thing in Python - I hit maximum recursion wall (or stack overflow). Is there way that a dynamic language like python can take advantage of these nice optimizations? Maybe it's possible to use a compiler instead of an interpreter to make this work? Just curious!

    Read the article

  • How do quickly search through a .csv file in Python

    - by Baldur
    I'm reading a 6 million entry .csv file with Python, and I want to be able to search through this file for a particular entry. Are there any tricks to search the entire file? Should you read the whole thing into a dictionary or should you perform a search every time? I tried loading it into a dictionary but that took ages so I'm currently searching through the whole file every time which seems wasteful. Could I possibly utilize that the list is alphabetically ordered? (e.g. if the search word starts with "b" I only search from the line that includes the first word beginning with "b" to the line that includes the last word beginning with "b") I'm using import csv. (a side question: it is possible to make csv go to a specific line in the file? I want to make the program start at a random line) Edit: I already have a copy of the list as an .sql file as well, how could I implement that into Python?

    Read the article

  • Link errors loading a Python extension for i386 MacOS that was compiled on a PPC

    - by deekoo
    I'm trying to compile a Python extension (written in C) on a PPC mac (running OS X 10.4, XCode 2.5), to run under Ren'Py on both PPC and i386 MacOS. The PPC version works; the i386 version fails to load with ImportError: dlopen(./fasttint_macos_i386.dylib, 2): Symbol not found: _PyType_GenericNew Referenced from: /Applications/Games/Demos/CuteKnightKingdom-demo-0.9.25.1-mac/CuteKnightKingdom-demo.app/Contents/Resources/autorun/game/fasttint_macos_i386.dylib Expected in: /Applications/Games/Demos/CuteKnightKingdom-demo-0.9.25.1-mac/CuteKnightKingdomdemo.app/Contents/Resources/autorun/game/fasttint_macos_i386.dylib As best I can tell, _PyType_GenericNew should be defined by Ren'Py's python - why is it trying to find an internal declaration for the symbol instead of the external one?

    Read the article

  • Clear command line output from Python [Eclipse]

    - by Tomas Lycken
    I'm using Eclipse for writing Python, and I want to be able to easily clear the screen. I've seen this question, and tried (among other things suggested there) the following solution import os def clear(): os.system('cls' if os.name == 'nt' else 'clear') but it doesn't entirely solve my problem. Instead of clearing the screen, the routine prints a small square (as if wanting to print an unknown character) to the command output window in Eclipse. Typing cls in the command line works perfectly fine, as does running a Python script with the above code from command line. But how can I make it look nice in Eclipse as well?

    Read the article

  • Allowing threads from python after calling a blocking i/o code in a python extension generated using

    - by SS
    I have written a python extension wrapping an existing C++ library live555 (wrapping RTSP client interface to be specific) in SWIG. The extension works when it is operated in a single thread, but as soon as I call the event loop function of the library, python interpreter never gets the control back. So if I create a scheduled task using threading.Timer right before calling the event loop, that task never gets executed once event loop starts. To fix this issue, I added Py_BEGIN_ALLOW_THREADS and Py_END_ALLOW_THREADS macros manually in the SWIG auto generated wrapper cxx file around every doEventLoop() function call. But now, I want to do the same (i.e. allow threads) when SWIG generates the code itself and not to change any code manually. Has anyone done something similar in SWIG? P.S. - I would also consider switching to any other framework (like SIP) to get this working. I selected SWIG over any other technology is because writing SWIG interface was really very easy and I just had to include the existing header files.

    Read the article

  • Converting excel files to python to frequency

    - by Jacob
    Essentially I've got an excel files with voltage in the first column, and time in the second. I want to find the period of the voltages, as it returns a graph of voltage in y axis and time in x axis with a periodicity, looking similar to a sine function. To find the frequency I have uploaded my excel file to python as I think this will make it easier- there may be something I've missed that will simplify this. So far in python I have: import xlrd import numpy as N import numpy.fft as F import matplotlib.pyplot as P wb = xlrd.open_workbook('temp7.xls') #LOADING EXCEL FILE wb.sheet_names() sh = wb.sheet_by_index(0) first_column = sh.col_values(1) #VALUES FROM EXCEL second_column = sh.col_values(2) #VALUES FROM EXCEL Now how do I find the frequency from this? Huge thanks to anyone who can help! Jacob

    Read the article

  • How to save big "database-like" class in python

    - by Rafal
    Hi there, I'm doing a project with reasonalby big DataBase. It's not a probper DB file, but a class with format as follows: DataBase.Nodes.Data=[[] for i in range(1,1000)] f.e. this DataBase is all together something like few thousands rows. Fisrt question - is the way I'm doing efficient, or is it better to use SQL, or any other "proper" DB, which I've never used actually. And the main question - I'd like to save my DataBase class with all record, and then re-open it with Python in another session. Is that possible, what tool should I use? cPickle - it seems to be only for strings, any other? In matlab there's very useful functionality named save workspace - it saves all Your variables to a file that You can open at another session - this would be vary useful in python!

    Read the article

  • running pdb from within pdb

    - by Andrew Farrell
    I'm debugging an script that I'm writing and the result of executing a statement from pdb does not make sense so my natural reaction is to try to trace it with pdb. To paraphrase: Yo dawg, I like python, so can you put my pdb in my pdb so I can debug while I debug?

    Read the article

  • Binomial test in Python

    - by Morlock
    I need to do a binomial test in Python that allows calculation for 'n' numbers of the order of 10000. I have implemented a quick binomial_test function using scipy.misc.comb, however, it is pretty much limited around n = 1000, I guess because it reaches the biggest representable number while computing factorials or the combinatorial itself. Here is my function: from scipy.misc import comb def binomial_test(n, k): """Calculate binomial probability """ p = comb(n, k) * 0.5**k * 0.5**(n-k) return p How could I use a native python (or numpy, scipy...) function in order to calculate that binomial probability? If possible, I need scipy 0.7.2 compatible code. Many thanks!

    Read the article

  • Python KMeans clustering words

    - by sadawd
    Dear Everyone I am interested to perform kmeans clustering on a list of words with the distance measure being Leveshtein. 1) I know there are a lot of frameworks out there, including scipy and orange that has a kmeans implementation. However they all require some sort of vector as the data which doesn't really fit me. 2) I need a good clustering implementation. I looked at python-clustering and realize that it doesn't a) return the sum of all the distance to each centroid, and b) it doesn't have any sort of iteration limit or cut off which ensures the quality of the clustering. python-clustering and the clustering algorithm on daniweb doesn't really work for me. Can someone find me a good lib? Google hasn't been my friend

    Read the article

  • Debugging segfault on swig/python/c++

    - by Pradyot
    I am trying to figure out what the best way to debug a segault with swig/python/c++. A core file is being generated. I have a basic MessageFactory(defined in c++ that provides a simple interface to accept a few strings as input and return a string as output). This interface is then specified in a .i file. swig is used to generate Wrapper.cpp as well as a MessageFactory.py from the .i file. This along with supporting files is compiled into a dynamic lib. The point of failure , is when the MessageFactory is instantiated within python code. Any suggestions on how I can go about debugging this? I've tried running the script within pdb, what I know from that is import on the generated MessageFactory.py is whats causing the seg-fault.

    Read the article

  • Google App Engine Python: get image upload size server-side

    - by goggin13
    I am building a Google App Engine App that lets users upload images; I have everything working fine, but I am struggling to find a way to ensure that the user does not upload an image too large (because I am resizing the images, so this crashes my python script). When a user uploads a large image, I get this error RequestTooLargeError: The request to API call images.Transform() was too large. I know that there is a size limitation on what GAE allows for it's image API, I am just trying to find a way to deal with this server side; something along the lines of if (image is too large): inform user else: proceed I haven't had any luck finding the right python code to do this; can anyone help me out?

    Read the article

  • Python: create a function to modify a list by reference not value

    - by Jonathan
    Hey all- I'm doing some performance-critical Python work and want to create a function that removes a few elements from a list if they meet certain criteria. I'd rather not create any copies of the list because it's filled with a lot of really large objects. Functionality I want to implement: def listCleanup(listOfElements): i = 0 for element in listOfElements: if(element.meetsCriteria()): del(listOfElements[i]) i += 1 return listOfElements myList = range(10000) myList = listCleanup(listOfElements) I'm not familiar with the low-level workings of Python. Is myList being passed by value or by reference? How can I make this faster? Is it possible to somehow extend the list class and implement listCleanup() within that? myList = range(10000) myList.listCleanup() Thanks- Jonathan

    Read the article

  • Port C's fread(&struct,....) to Python

    - by user287669
    Hey, I'm really struggling with this one. I'am trying to port a small piece of someone else's code to Python and this is what I have: typedef struct { uint8_t Y[LUMA_HEIGHT][LUMA_WIDTH]; uint8_t Cb[CHROMA_HEIGHT][CHROMA_WIDTH]; uint8_t Cr[CHROMA_HEIGHT][CHROMA_WIDTH]; } __attribute__((__packed__)) frame_t; frame_t frame; while (! feof(stdin)) { fread(&frame, 1, sizeof(frame), stdin); // DO SOME STUFF } Later I need to access the data like so: frame.Y[x][y] So I made a Class 'frame' in Python and inserted the corresponding variables(frame.Y, frame.Cb, frame.Cr). I have tried to sequentially map the data from Y[0][0] to Cr[MAX][MAX], even printed out the C struct in action but didn't manage to wrap my head around the method used to put the data in there. I've been struggling overnight with this and have to get back to the army tonight, so any immediate help is very welcome and appreciated. Thanks

    Read the article

  • MS Analysis Services OLAP API for Python

    - by Kaloyan Todorov
    I am looking for a way to connect to a MS Analysis Services OLAP cube, run MDX queries, and pull the results into Python. In other words, exactly what Excel does. Is there a solution in Python that would let me do that? Someone with a similar question going pointed to Django's ORM. As much as I like the framework, this is not what I am looking for. I am also not looking for a way to pull rows and aggregate them -- that's what Analysis Services is for in the first place. Ideas? Thanks.

    Read the article

  • Cleanest way to run/debug python programs in windows

    - by YGA
    Python for Windows by default comes with IDLE, which is the barest-bones IDE I've ever encountered. For editing files, I'll stick to emacs, thank you very much. However, I want to run programs in some other shell than the crappy windows command prompt, which can't be widened to more than 80 characters. IDLE lets me run programs in it if I open the file, then hit F5 (to go Run- Run Module). I would rather like to just "run" the command, rather than going through the rigmarole of closing the emacs file, loading the IDLE file, etc. A scan of google and the IDLE docs doesn't seem to give much help about using IDLE's shell but not it's IDE. Any advice from the stack overflow guys? Ideally I'd either like advice on running programs using IDLE's shell advice on other ways to run python programs in windows outside of IDLE or "cmd". Thanks, /YGA

    Read the article

  • trying to use code_swarm but Im having some python scripting problems

    - by theprojectabot
    I am having issues running this: link-mbp:codeswarm-0.1 benb$ python convert_logs/convert_logs.py -perforce-path Traceback (most recent call last): File “convert_logs/convert_logs.py”, line 408, in main() File “convert_logs/convert_logs.py”, line 350, in main files = run_marshal(’p4 -G describe -s “‘ + changelist['change'] + ‘”‘) KeyError: ‘change’ link-mbp:codeswarm-0.1 benb$ I am trying to use code_swarm from this link http://blog.perforce.com/blog/?p=780&cpage=1#comment-965 to visualize my codebase changes. if I run p4 changes everything shows correct but the code in this python script doesnt seem to process correctly... if I run p4 describe on a a changelist number it correctly reports ideas?

    Read the article

< Previous Page | 60 61 62 63 64 65 66 67 68 69 70 71  | Next Page >