Search Results

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

Page 218/548 | < Previous Page | 214 215 216 217 218 219 220 221 222 223 224 225  | Next Page >

  • installing Gevent on OSX

    - by Dev9281
    >>> import gevent Traceback (most recent call last): File "<stdin>", line 1, in <module> File "build/bdist.macosx-10.6-universal/egg/gevent/__init__.py", line 41, in <module> File "build/bdist.macosx-10.6-universal/egg/gevent/core.py", line 7, in <module> File "build/bdist.macosx-10.6-universal/egg/gevent/core.py", line 6, in __bootstrap__ ImportError: dlopen(/Users/admin/.python-eggs/gevent-0.13.6-py2.6-macosx-10.6-universal.egg-tmp/gevent/core.so, 2): Symbol not found: _event_global_current_base_ Referenced from: /Users/admin/.python-eggs/gevent-0.13.6-py2.6-macosx-10.6-universal.egg-tmp/gevent/core.so Expected in: flat namespace in /Users/admin/.python-eggs/gevent-0.13.6-py2.6-macosx-10.6-universal.egg-tmp/gevent/core.so What's this about? I did not get any errors during the installation

    Read the article

  • Is there any way to isolate the python2.7 , mod_wsgi installation from main environment

    - by user31
    I have many local virtual machines for building the django websites. I find it very hard to configure all the machines with mod_wsgi , python and all that installation issues. Is there any way that i can install even python 2.7 , mod_wsgi etc and all that inside the virtual environment folder so that i can just copy paste that folder in my live server and i don't need to mess with mos_wsgi , python 2.7 and other issues. Is it possible or even any close variation of that so that puting the site to live servers is very easy and everything which is needed by site should be included locally I also face many problems when i need to move the django sites across servers

    Read the article

  • How do I prevent rpmbuild form injecting requirements into RPM package?

    - by Basilevs
    I'm creating an RPM package from native Python 2.5 one. Out corporate policy is to use python2.4 by default, so I'm adding a string Requires: python25 to a .spec file. When I look at created RPM file though, i see the following dependencies: rpm -qR -p ZSI-2.1_a1-py25.noarch.rpm /usr/bin/python2.5 python(abi) = 2.5 python25 rpmlib(CompressedFileNames) <= 3.0.4-1 rpmlib(PayloadFilesHavePrefix) <= 4.0-1 Dependency added by me is present, but other dependencies are also here. I'm unable to provide python(abi) = 2.5 dependency, because of dumb python25 package generated by our IT department where provides tag is incorrect. How do I remove automatically added dependencies from generated RPM?

    Read the article

  • Apache: Use Specific Applicaion for CGI scripts

    - by RandomInsano
    I have two servers, one in production and one for development. The production server is Solaris, dev is FreeBSD. Because of this, python is installed in different directories. I'm using Python right now for making CGI scripts, and needing to remember to swap my hashbangs when I copy from dev to production is a little annoying (Same issue for SVN updates depending on which server I'm comitting from). Is there a way to configure apache so that I no longer need to hashbangs? Like, if it would lauch python and supply the CGI script for it? Might be a bit of a stretch, but no harm in asking

    Read the article

  • Dropbox.py on RHEL 6

    - by Timothy R. Butler
    I'm trying to run a headless install of Dropbox on RHEL 6. The daemon seems to be running, but when I try to use Dropbox's associated dropbox.py tool to control the daemon, it fails to run with the following error: Traceback (most recent call last): File "./dropbox.py", line 26, in <module> import locale File "/usr/lib64/python2.6/locale.py", line 202, in <module> import re, operator ImportError: /home/dropbox/.dropbox-dist/operator.so: undefined symbol: _PyUnicodeUCS2_AsDefaultEncodedString I'm running the current RHEL build of Python 2.6: root@cedar [/home/dropbox/.dropbox-dist]# rpm -qv python python-2.6.6-29.el6_3.3.x86_64 (I'm not sure if this would be better suited to Stack Overflow since it is on the verge of being a programming issue, but since I'm trying to use a program straight from Dropbox, I placed it here.)

    Read the article

  • Where is OS X's $PATH set?

    - by thepurplepixel
    I have a little $PATH problem: I just reinstalled MacPorts, and my path contains the MacPorts directories as it should at the beginning of $PATH. However, despite me having no such setting in my ~/.bashrc, ~/.bash_profile or ~/.profile, /Library/Frameworks/Python.framework/Versions/2.6/bin is somehow getting appended to the beginning of my $PATH: 0 07:15:11pm ~ $ echo $PATH /Library/Frameworks/Python.framework/Versions/2.6/bin:/opt/local/bin:/opt/local/sbin:/usr/bin:/bin:/usr/sbin:/sbin:/usr/local/bin:/usr/X11/bin I'd like to remove it as the MacPorts version of Python is newer. This must be appended after all the above-listed files are read, but I can't think of where. There is no mention of this in /etc/profile, /etc/bashrc or /etc/paths. Any assistance would be greatly appreciated. Thanks!

    Read the article

  • I am getting this error on using matplotlib

    - by Arun Abraham
    I get this error on typing this in python command prompt: import matplotlib.pyplot as plt Traceback (most recent call last): File "<pyshell#1>", line 1, in <module> import matplotlib.pyplot as plt File "/Library/Python/2.7/site-packages/matplotlib-1.3.x-py2.7-macosx-10.8-intel.egg/matplotlib/pyplot.py", line 97, in <module> _backend_mod, new_figure_manager, draw_if_interactive, _show = pylab_setup() File "/Library/Python/2.7/site-packages/matplotlib-1.3.x-py2.7-macosx-10.8-intel.egg/matplotlib/backends/__init__.py", line 25, in pylab_setup globals(),locals(),[backend_name]) File "/Library/Python/2.7/site-packages/matplotlib-1.3.x-py2.7-macosx-10.8-intel.egg/matplotlib/backends/backend_macosx.py", line 21, in <module> from matplotlib.backends import _macosx ImportError: dlopen(/Library/Python/2.7/site-packages/matplotlib-1.3.x-py2.7-macosx-10.8-intel.egg/matplotlib/backends/_macosx.so, 2): Library not loaded: /System/Library/Frameworks/CoreText.framework/Versions/A/CoreText Referenced from: /Library/Python/2.7/site-packages/matplotlib-1.3.x-py2.7-macosx-10.8-intel.egg/matplotlib/backends/_macosx.so Reason: image not found Can someone suggest me, how i can fix this ? I had installed all the packages with this shell script https://github.com/fonnesbeck/ScipySuperpack Is there anything that i am missing ? Any additional configuration ?

    Read the article

  • error when plotting log'd array in matplotlib/scipy/numpy

    - by user248237
    I have two arrays and I take their logs. When I do that and try to plot their scatter plot, I get this error: File "/Library/Python/2.6/site-packages/matplotlib-1.0.svn_r7892-py2.6-macosx-10.6-universal.egg/matplotlib/pyplot.py", line 2192, in scatter ret = ax.scatter(x, y, s, c, marker, cmap, norm, vmin, vmax, alpha, linewidths, faceted, verts, **kwargs) File "/Library/Python/2.6/site-packages/matplotlib-1.0.svn_r7892-py2.6-macosx-10.6-universal.egg/matplotlib/axes.py", line 5384, in scatter self.add_collection(collection) File "/Library/Python/2.6/site-packages/matplotlib-1.0.svn_r7892-py2.6-macosx-10.6-universal.egg/matplotlib/axes.py", line 1391, in add_collection self.update_datalim(collection.get_datalim(self.transData)) File "/Library/Python/2.6/site-packages/matplotlib-1.0.svn_r7892-py2.6-macosx-10.6-universal.egg/matplotlib/collections.py", line 153, in get_datalim offsets = transOffset.transform_non_affine(offsets) File "/Library/Python/2.6/site-packages/matplotlib-1.0.svn_r7892-py2.6-macosx-10.6-universal.egg/matplotlib/transforms.py", line 1924, in transform_non_affine self._a.transform(points)) File "/Library/Python/2.6/site-packages/matplotlib-1.0.svn_r7892-py2.6-macosx-10.6-universal.egg/matplotlib/transforms.py", line 1420, in transform return affine_transform(points, mtx) ValueError: Invalid vertices array. the code is simply: myarray_x = log(my_array[:, 0]) myarray_y = log(my_array[:, 1]) plt.scatter(myarray_x, myarray_y) any idea what could be causing this? thanks.

    Read the article

  • ‘Empty’ results from MQL Query. Freebase Schema: /film/film/starring & /film/actor/film

    - by user1879631
    First post here, so I hope this is enough detail. I started using freebase-python today to get film information for a program that I’m working on. One thing that I need to grab is a list of actors that starred in a film. I’ve followed some tutorials and guides on the way to do this, and can get a list of films for a director or the director of a film, but when I try to do the same with an actor or a film’s cast, I get ‘null’ results. I have the same problem in both Python and the Freebase MQL Query Editor, and you can see what I've tried below. Links to all of the examples below written in the editor can be found here, as Stack Overflow wouldn't let me post links underneath each example on my first post! Working director query in Python: import freebase fb = freebase.mqlread q = {'type':'/film/film', 'name':'Inception', 'directed_by':[]} fb(q) Working director's filmography query in Python: import freebase fb = freebase.mqlread q = {'type':'/film/director', 'name': 'Christopher Nolan', 'film':[]} fb(q) Based on these tests, I tried to do the same with actors, but with odd results: Not working cast list query in Python: import freebase fb = freebase.mqlread q = {'type':'/film/film', 'name':'Inception', 'starring':[]} fb(q) Not working actor's filmography query in Python: import freebase fb = freebase.mqlread q = {'type':'/film/actor', 'name':'Leonardo DiCaprio', 'film':[]} fb(q) Strangely, I get an accurate number of actors/films back, but no names. Does anyone have any idea what the problem might be? Thanks a lot, I'd appreciate any advice.

    Read the article

  • Distutils - Where Am I going wrong?

    - by RJBrady
    I wanted to learn how to create python packages, so I visited http://docs.python.org/distutils/index.html. For this exercise I'm using Python 2.6.2 on Windows XP. I followed along with the simple example and created a small test project: person/ setup.py person/ __init__.py person.py My person.py file is simple: class Person(object): def __init__(self, name="", age=0): self.name = name self.age = age def sound_off(self): print "%s %d" % (self.name, self.age) And my setup.py file is: from distutils.core import setup setup(name='person', version='0.1', packages=['person'], ) I ran python setup.py sdist and it created MANIFEST, dist/ and build/. Next I ran python setup.py install and it installed it to my site packages directory. I run the python console and can import the person module, but I cannot import the Person class. >>>import person >>>from person import Person Traceback (most recent call last): File "<stdin>", line 1, in <module> ImportError: cannot import name Person I checked the files added to site-packages and checked the sys.path in the console, they seem ok. Why can't I import the Person class. Where did I go wrong?

    Read the article

  • lightweight webserver to integrate on client end.

    - by Gopal
    Hi ,... I need to create a python module that will be installed on end-user machines. One of the scripts in that module should be able to receive http POSTS (usually with some JSON formatted data in the body) and then pass on that data to an appropriate python script. I can think of two ways to do this: a) Open a listening server socket on port 80, wait for that http request to come in, parse it and then pass that data to another python script depending on the url that arrived. This method will not require the end-user to install a webserver. End user only has to install the python module. b) Have a mini-webserver installed along with the python module. The webserver will do the same job as [a] via CGI without me requiring to write the CGI functionality. But then the user will have to install the web-server (ie., the hassle of yet another install). Would like to avoid that if possible. IF [b] is the easier option, what is the smallest simplest webserver there is (preferably one that can be packaged as part of the python module itself so that it does not have to be separately installed). Must be opensource of course. regards Gopal

    Read the article

  • Directly call distutils' or setuptools' setup() function with command name/options, without parsing

    - by Ryan B. Lynch
    I'd like to call Python's distutils' or setuptools' setup() function in a slightly unconventional way, but I'm not sure whether distutils is meant for this kind of usage. As an example, let's say I currently have a 'setup.py' file, which looks like this (lifted verbatim from the distutils docs--the setuptools usage is almost identical): from distutils.core import setup setup(name='Distutils', version='1.0', description='Python Distribution Utilities', author='Greg Ward', author_email='[email protected]', url='http://www.python.org/sigs/distutils-sig/', packages=['distutils', 'distutils.command'], ) Normally, to build just the .spec file for an RPM of this module, I could run python setup.py bdist_rpm --spec-only, which parses the command line and calls the 'bdist_rpm' code to handle the RPM-specific stuff. The .spec file ends up in './dist'. How can I change my setup() invocation so that it runs the 'bdist_rpm' command with the '--spec-only' option, WITHOUT parsing command-line parameters? Can I pass the command name and options as parameters to setup()? Or can I manually construct a command line, and pass that as a parameter, instead? NOTE: I already know that I could call the script in a separate process, with an actual command line, using os.system() or the subprocess module or something similar. I'm trying to avoid using any kind of external command invocations. I'm looking specifically for a solution that runs setup() in the current interpreter. For background, I'm converting some release-management shell scripts into a single Python program. One of the tasks is running 'setup.py' to generate a .spec file for further pre-release testing. Running 'setup.py' as an external command, with its own command line options, seems like an awkward method, and it complicates the rest of the program. I feel like there may be a more Pythonic way.

    Read the article

  • Add Keyboard Binding To Existing Emacs Mode

    - by Sean M
    I'm attempting my first modification of emacs. I recorded a little keyboard macro and had emacs spit it out as elisp, resulting in: (setq add-docstring "\C-rdef\C-n\C-a\C-m\C-p\C-i\C-u6\"\C-u3\C-b") (global-set-key "\C-c\C-d" 'add-docstring) Searching the emacs reference, though, revealed that C-c C-d is already bound in diff mode. I don't plan on using diff mode, but the future is unknowable and I'd like to not lay a trap for myself. So I'd like this keybinding to only operate in python mode, where it tries to help me add docstrings. In my /usr/share/emacs/23.whatever/list/progmodes, I found python.elc and python.el.gz. I unzipped python.el.gz and got a readable version of the elisp file. Now, though, the documentation becomes opaque to me. How can I add my key binding to the python mode, instead of globally? Is it possible, for bonus points, to apply the changes to python mode without restarting emacs or closing open files? It's the self-modifying editor, I figure there's a good chance that it's possible.

    Read the article

  • BeautifulSoup HTMLParseError. What's wrong with this?

    - by user1915496
    This is my code: from bs4 import BeautifulSoup as BS import urllib2 url = "http://services.runescape.com/m=news/recruit-a-friend-for-free-membership-and-xp" res = urllib2.urlopen(url) soup = BS(res.read()) other_content = soup.find_all('div',{'class':'Content'})[0] print other_content Yet an error comes up: /Library/Python/2.7/site-packages/bs4/builder/_htmlparser.py:149: RuntimeWarning: Python's built-in HTMLParser cannot parse the given document. This is not a bug in Beautiful Soup. The best solution is to install an external parser (lxml or html5lib), and use Beautiful Soup with that parser. See http://www.crummy.com/software/BeautifulSoup/bs4/doc/#installing-a-parser for help. "Python's built-in HTMLParser cannot parse the given document. This is not a bug in Beautiful Soup. The best solution is to install an external parser (lxml or html5lib), and use Beautiful Soup with that parser. See http://www.crummy.com/software/BeautifulSoup/bs4/doc/#installing-a-parser for help.")) Traceback (most recent call last): File "web.py", line 5, in <module> soup = BS(res.read()) File "/Library/Python/2.7/site-packages/bs4/__init__.py", line 172, in __init__ self._feed() File "/Library/Python/2.7/site-packages/bs4/__init__.py", line 185, in _feed self.builder.feed(self.markup) File "/Library/Python/2.7/site-packages/bs4/builder/_htmlparser.py", line 150, in feed raise e I've let two other people use this code, and it works for them perfectly fine. Why is it not working for me? I have bs4 installed...

    Read the article

  • What could cause xmlrpclib.ResponseError: ResponseError() ?

    - by Tom
    Hi, I am experimenting with XML-RPC. I have the following server script (python): from SimpleXMLRPCServer import SimpleXMLRPCServer server = SimpleXMLRPCServer(('localhost', 9000)) def return_input(someinput): return someinput server.register_function(return_input) try: print 'ctrl-c to stop server' server.serve_forever() except KeyboardInterrupt: print 'stopping' and the following client script: import xmlrpclib server = xmlrpclib.ServerProxy('http://www.example.com/pathto/xmlrpcTester2.py') print server.return_input('some input') I have tested this locally and it works fine. All it does it spit out the input fron the client script, which is right. However, when I try to do it on a remote server I get the following error: Traceback (most recent call last): File "client.py", line 4, in <module> print server.return_input('some input') File "/System/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/xmlrpclib.py", line 1199, in __call__ return self.__send(self.__name, args) File "/System/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/xmlrpclib.py", line 1489, in __request verbose=self.__verbose File "/System/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/xmlrpclib.py", line 1253, in request return self._parse_response(h.getfile(), sock) File "/System/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/xmlrpclib.py", line 1392, in _parse_response return u.close() File "/System/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/xmlrpclib.py", line 836, in close raise ResponseError() xmlrpclib.ResponseError: ResponseError() Any ideas what could cause this? Thanks in advance for your help.

    Read the article

  • Python 3.4 adds re.fullmatch()

    - by Jan Goyvaerts
    Python 3.4 does not bring any changes to its regular expression syntax compared to previous 3.x releases. It does add one new function to the re module called fullmatch(). This function takes a regular expression and a subject string as its parameters. It returns True if the regular expression can match the string entirely. It returns False if the string cannot be matched or if it can only be matched partially. This is useful when using a regular expression to validate user input. Do note that fullmatch() will return True if the subject string is the empty string and the regular expression can find zero-length matches. A zero-length match of a zero-length string is a complete match. So if you want to check whether the user entered a sequence of digits, use \d+ rather than \d* as the regex.

    Read the article

  • Sending keystrokes using Python

    - by Rudi Strydom
    I am trying to build a remote control application to control media on my Ubuntu. Does anyone know a way in order to accomplish this. The media keys in particular. Thank you. EIDT: I have tried using XTE, but is seems python in truncating the input or there is a limit or something which means that you can't do Ctrl + Key key presses, which wont suit my needs. I also tried uinput, but alas you need to run it as root, which also will not quite my needs. Now I am looking at EVDEV which seems promicing, that is if I can get it working.

    Read the article

  • Rendering citations and references in HTML using PHP/Perl/Python/

    - by Nick
    Is there a PHP/Perl/Python/... library for picking citations out of an HTML file and rendering a nice list of references at the bottom, like in Wikipedia? I'm developing a website with heavily-sourced content, and I'd really like to have automatically-generated lists of formatted references, like in Wikipedia. (Check out their philosophy page, and see how the superscript numbered citations interact with the references at the bottom. This is all dynamically generated, automatically ordered & linked.) They do it really well: the citations are linked to the references (which are backlinked to the citations), when you click on one of the links, the target is highlighted, etc. I'm tempted to build the site on MediaWiki just for this one feature, but it seems like overkill. Do I have any options?

    Read the article

  • Python - calculate multinomial probability density functions on large dataset?

    - by Seafoid
    Hi, I originally intended to use MATLAB to tackle this problem but the inbuilt functions has limitations that do not suit my goal. The same limitation occurs in NumPy. I have two tab-delimited files. The first is a file showing amino acid residue, frequency and count for an in-house database of protein structures, i.e. A 0.25 1 S 0.25 1 T 0.25 1 P 0.25 1 The second file consists of quadruplets of amino acids and the number of times they occur, i.e. ASTP 1 Note, there are 8,000 such quadruplets. Based on the background frequency of occurence of each amino acid and the count of quadruplets, I aim to calculate the multinomial probability density function for each quadruplet and subsequently use it as the expected value in a maximum likelihood calculation. The multinomial distribution is as follows: f(x|n, p) = n!/(x1!*x2!*...*xk!)*((p1^x1)*(p2^x2)*...*(pk^xk)) where x is the number of each of k outcomes in n trials with fixed probabilities p. n is 4 four in all cases in my calculation. I have created three functions to calculate this distribution. # functions for multinomial distribution def expected_quadruplets(x, y): expected = x*y return expected # calculates the probabilities of occurence raised to the number of occurrences def prod_prob(p1, a, p2, b, p3, c, p4, d): prob_prod = (pow(p1, a))*(pow(p2, b))*(pow(p3, c))*(pow(p4, d)) return prob_prod # factorial() and multinomial_coefficient() work in tandem to calculate C, the multinomial coefficient def factorial(n): if n <= 1: return 1 return n*factorial(n-1) def multinomial_coefficient(a, b, c, d): n = 24.0 multi_coeff = (n/(factorial(a) * factorial(b) * factorial(c) * factorial(d))) return multi_coeff The problem is how best to structure the data in order to tackle the calculation most efficiently, in a manner that I can read (you guys write some cryptic code :-)) and that will not create an overflow or runtime error. To data my data is represented as nested lists. amino_acids = [['A', '0.25', '1'], ['S', '0.25', '1'], ['T', '0.25', '1'], ['P', '0.25', '1']] quadruplets = [['ASTP', '1']] I initially intended calling these functions within a nested for loop but this resulted in runtime errors or overfloe errors. I know that I can reset the recursion limit but I would rather do this more elegantly. I had the following: for i in quadruplets: quad = i[0].split(' ') for j in amino_acids: for k in quadruplets: for v in k: if j[0] == v: multinomial_coefficient(int(j[2]), int(j[2]), int(j[2]), int(j[2])) I haven'te really gotten to how to incorporate the other functions yet. I think that my current nested list arrangement is sub optimal. I wish to compare the each letter within the string 'ASTP' with the first component of each sub list in amino_acids. Where a match exists, I wish to pass the appropriate numeric values to the functions using indices. Is their a better way? Can I append the appropriate numbers for each amino acid and quadruplet to a temporary data structure within a loop, pass this to the functions and clear it for the next iteration? Thanks, S :-)

    Read the article

  • Programmatically specifying Django model attributes

    - by mojbro
    Hi! I would like to add attributes to a Django models programmatically, at run time. For instance, lets say I have a Car model class and want to add one price attribute (database column) per currency, given a list of currencies. What is the best way to do this? I had an approach that I thought would work, but it didn't exactly. This is how I tried doing it, using the car example above: from django.db import models class Car(models.Model): name = models.CharField(max_length=50) currencies = ['EUR', 'USD'] for currency in currencies: Car.add_to_class('price_%s' % currency.lower(), models.IntegerField()) This does seem to work pretty well at first sight: $ ./manage.py syncdb Creating table shop_car $ ./manage.py dbshell shop=# \d shop_car Table "public.shop_car" Column | Type | Modifiers -----------+-----------------------+------------------------------------------------------- id | integer | not null default nextval('shop_car_id_seq'::regclass) name | character varying(50) | not null price_eur | integer | not null price_usd | integer | not null Indexes: "shop_car_pkey" PRIMARY KEY, btree (id) But when I try to create a new Car, it doesn't really work anymore: >>> from shop.models import Car >>> mycar = Car(name='VW Jetta', price_eur=100, price_usd=130) >>> mycar <Car: Car object> >>> mycar.save() Traceback (most recent call last): File "<console>", line 1, in <module> File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/django/db/models/base.py", line 410, in save self.save_base(force_insert=force_insert, force_update=force_update) File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/django/db/models/base.py", line 495, in save_base result = manager._insert(values, return_id=update_pk) File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/django/db/models/manager.py", line 177, in _insert return insert_query(self.model, values, **kwargs) File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/django/db/models/query.py", line 1087, in insert_query return query.execute_sql(return_id) File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/django/db/models/sql/subqueries.py", line 320, in execute_sql cursor = super(InsertQuery, self).execute_sql(None) File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/django/db/models/sql/query.py", line 2369, in execute_sql cursor.execute(sql, params) File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/django/db/backends/util.py", line 19, in execute return self.cursor.execute(sql, params) ProgrammingError: column "price_eur" specified more than once LINE 1: ...NTO "shop_car" ("name", "price_eur", "price_usd", "price_eur... ^

    Read the article

  • How to use Python list comprehension (or such) for retrieving rows when using MySQLdb?

    - by Erik Nygren
    Hey all, I use MySQLdb a lot when dealing with my webserver. I often find myself repeating the lines: row = cursor.fetchone() while row: do_processing(row) row = cursor.fetchone() Somehow this strikes me as somewhat un-pythonic. Is there a better, one-line way to accomplish the same thing, along the lines of inline assignment in C: while (row = do_fetch()) { do_processing(row); } I've tried figuring out the syntax using list comprehensions, but I can't seem to figure it out. Any recommendations? Thanks, Erik

    Read the article

  • How to write the Visitor Pattern for Abstract Syntax Tree in Python?

    - by bodacydo
    My collegue suggested me to write a visitor pattern to navigate the AST. Can anyone tell me more how would I start writing it? As far as I understand, each Node in AST would have visit() method (?) that would somehow get called (from where?). That about concludes my understanding. To simplify everything, suppose I have nodes Root, Expression, Number, Op and the tree looks like this: Root | Op(+) / \ / \ Number(5) \ Op(*) / \ / \ / \ Number(2) Number(444) Can anyone think of how the visitor pattern would visit this tree to produce output: 5 + 2 * 444 Thanks, Boda Cydo.

    Read the article

  • Python: speed up removal of every n-th element from list.

    - by ChristopheD
    I'm trying to solve this programming riddle and althought the solution (see code below) works correct, it is too slow for succesful submission. Any pointers as how to make this run faster? (removal of every n-th element from a list)? Or suggestions for a better algorithm to calculate the same; seems I can't think of anything else then brute-force for now... Basically the task at hand is: GIVEN: L = [2,3,4,5,6,7,8,9,10,11,........] 1. Take the first remaining item in list L (in the general case 'n'). Move it to the 'lucky number list'. Then drop every 'n-th' item from the list. 2. Repeat 1 TASK: Calculate the n-th number from the 'lucky number list' ( 1 <= n <= 3000) My current code (it calculates the 3000 first lucky numbers in about a second on my machine - but unfortunately too slow): """ SPOJ Problem Set (classical) 1798. Assistance Required URL: http://www.spoj.pl/problems/ASSIST/ """ sieve = range(3, 33900, 2) luckynumbers = [2] while True: wanted_n = input() if wanted_n == 0: break while len(luckynumbers) < wanted_n: item = sieve[0] luckynumbers.append(item) items_to_delete = set(sieve[::item]) sieve = filter(lambda x: x not in items_to_delete, sieve) print luckynumbers[wanted_n-1]

    Read the article

< Previous Page | 214 215 216 217 218 219 220 221 222 223 224 225  | Next Page >