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python Programming Glossary: thisWhat is a metaclass in Python? http://stackoverflow.com/questions/100003/what-is-a-metaclass-in-python concepts well let's say they're just OO concepts but this one is tricky. I know it has something to do with introspection.. python oop metaclass python datamodel share improve this question Classes as objects Before understanding metaclasses.. is itself capable of creating objects the instances and this is why it's a class . But still it's an object and therefore..
The Python yield keyword explained http://stackoverflow.com/questions/231767/the-python-yield-keyword-explained What does it do For example I'm trying to understand this code def node._get_child_candidates self distance min_dist max_dist.. distance max_dist self._median yield self._rightchild And this is the caller result candidates list self while candidates node.. mspace . python iterator generator yield share improve this question To understand what yield does you must understand..
How do you split a list into evenly sized chunks in Python? http://stackoverflow.com/questions/312443/how-do-you-split-a-list-into-evenly-sized-chunks-in-python and operate on it. There are some obvious ways to do this like keeping a counter and two lists and when the second list.. and empty the second list for the next round of data but this is potentially extremely expensive. I was wondering if anyone.. I was wondering if anyone had a good solution to this for lists of any length e.g. using generators. This should work..
http://stackoverflow.com/questions/509211/pythons-slice-notation you have a good reference on Python's slice notation To me this notation needs a bit of picking up. It looks extremely powerful.. am looking for a good guide. python slice share improve this question It's pretty simple really a start end # items start..
What is a metaclass in Python? http://stackoverflow.com/questions/100003/what-is-a-metaclass-in-python creates in memory an object with the name ObjectCreator . This object the class is itself capable of creating objects the instances.. objects and you can create a class on the fly dynamically. This is what Python does when you use the keyword class and it does.. but one way is to set __metaclass__ at the module level. This way all classes of this module will be created using this metaclass..
Fastest way to list all primes below N in python http://stackoverflow.com/questions/2068372/fastest-way-to-list-all-primes-below-n-in-python way to list all primes below N in python This is the best algorithm I could come up with after struggling.. 1 1.1499958793645562 Can it be made even faster EDIT This code has a flaw Since numbers is an unordered set there is no.. wheel criterion 2 3 5 30 Copyright 2009 by zerovolt.com This code is free for non commercial purposes in which case you can..
The Python yield keyword explained http://stackoverflow.com/questions/231767/the-python-yield-keyword-explained who made a great Python library for metric spaces. This is the link to the complete source http well adjusted.de ~jrschulz.. distance min_dist max_dist return result This code contains several smart parts The loop iterates on a list.. so it will work with strings lists tuples and generators This is called duck typing and is one of the reason why Python is..
How do you split a list into evenly sized chunks in Python? http://stackoverflow.com/questions/312443/how-do-you-split-a-list-into-evenly-sized-chunks-in-python to this for lists of any length e.g. using generators. This should work l range 1 1000 print chunks l 10 1..10 11..20 ....
How can I represent an 'Enum' in Python? http://stackoverflow.com/questions/36932/how-can-i-represent-an-enum-in-python enums 'reverse_mapping' reverse return type 'Enum' enums This overwrites anything with that name but it is useful for rendering..
Flattening a shallow list in Python http://stackoverflow.com/questions/406121/flattening-a-shallow-list-in-python list mi.image_set.all for mi in list_of_menuitems This is the correct syntax for a nested list comprehension Brilliant.. s which it appears that you're using in the question. Edit This is probably as good as a reduce anyway because reduce will have..
How to improve performance of this code? http://stackoverflow.com/questions/4295799/how-to-improve-performance-of-this-code What you can do is convert closedlist into a set object. This keeps hashes of its items so the in operator is much more efficient..
How to install pip on windows? http://stackoverflow.com/questions/4750806/how-to-install-pip-on-windows up to date way to install pip on windows Additional edits This question was asked originally for Python 2.x but the answers.. dire until the language ships with a package manager. This is what languages that care about community do eg. Ruby with..
Old style and new style classes in Python http://stackoverflow.com/questions/54867/old-style-and-new-style-classes-in-python the class of x but type x is always type 'instance' . This reflects the fact that all old style instances independently..
Python: How do I pass a variable by reference? http://stackoverflow.com/questions/986006/python-how-do-i-pass-a-variable-by-reference As @Andrea's answer shows you could return the new value. This doesn't change the way things are passed in but does let you..
SQLAlchemy: Relation table with composite primary key http://stackoverflow.com/questions/10525797/sqlalchemy-relation-table-with-composite-primary-key session.commit session.expunge_all print ' ' 80 # test KO THIS SHOULD FAIL VIOLATING FK constraint a_11 get_action ac 11 a_22..
Python UnicodeDecodeError: 'ascii' codec can't decode byte 0xe2 ordinal not in range(128) http://stackoverflow.com/questions/10934184/python-unicodedecodeerror-ascii-codec-cant-decode-byte-0xe2-ordinal-not-in-r to a late fee of 10 plus 3.00 dollars per day. ACCEPTED THIS dateContract at localContract . ___________________________________________________..
Crawling LinkedIn while authenticated with Scrapy http://stackoverflow.com/questions/10953991/crawling-linkedin-while-authenticated-with-scrapy n # Now the crawling can begin.. return self.initialized # THIS LINE FIXED THE LAST PROBLEM else self.log n n nFailed Bad times..
Creating dynamically named variables from user input http://stackoverflow.com/questions/11354214/creating-dynamically-named-variables-from-user-input
Reason for unintuitive UnboundLocalError behaviour http://stackoverflow.com/questions/1188944/reason-for-unintuitive-unboundlocalerror-behaviour def aaaargh alist for x in alist print a a 23 what is THIS code supposed to do in your desired variant on Python Have the..
Keyboard Interrupts with python's multiprocessing Pool http://stackoverflow.com/questions/1408356/keyboard-interrupts-with-pythons-multiprocessing-pool pool.map slowly_square range 40 except KeyboardInterrupt # THIS PART NEVER EXECUTES. pool.terminate print You cancelled the..
Picklable data containers that are dumpable in the current namespace http://stackoverflow.com/questions/14716727/picklable-data-containers-that-are-dumpable-in-the-current-namespace code is ugly mainly YOU SHOULDN'T BE DOING SOMETHING LIKE THIS P and when using exec the usual warnings apply Make sure you..
How do you round UP a number in Python? http://stackoverflow.com/questions/2356501/how-do-you-round-up-a-number-in-python number .5 but it won't work in edge cases. Example WAIT THIS WORKED Please advise. python floating point integer rounding..
Schedule a repeating event in Python 3 http://stackoverflow.com/questions/2398661/schedule-a-repeating-event-in-python-3 sched.scheduler time.time time.sleep # Schedule the event. THIS IS UGLY for i in range 60 scheduler.enter 3600 i 1 query_rate_limit..
How to send an e-mail from a Python script that is being run on “Google App Engine”? http://stackoverflow.com/questions/3595438/how-to-send-an-e-mail-from-a-python-script-that-is-being-run-on-google-app-engi message from a Python script. I have found this script IN THIS TUTORIAL Here is the same script as a quote import sys smtplib..
How to make python 3 print() utf8 http://stackoverflow.com/questions/3597480/how-to-make-python-3-print-utf8 string in Python 3.X. TestText2 TestText.encode 'utf8' # THIS is just bytes in UTF 8. Now to send UTF 8 to stdout regardless..
Linux: Pipe into Python (ncurses) script, stdin and termios http://stackoverflow.com/questions/3999114/linux-pipe-into-python-ncurses-script-stdin-and-termios blabla HERE at end before curses TYPING blabla HERE # # AT THIS POINT # in this case curses window is shown with the text 'TYPING.. blabla HERE at end before curses TYPING blabla HERE # # AT THIS POINT # script simply exits nothing is shown # ################..
http://stackoverflow.com/questions/5520918/python-irc-bot-question hi print hi mynick hi bot hi MY QUESTION IS HOW TO DO THIS python irc bots share improve this question If you're not..
Compiling Python 2.6.6 and need for external packages wxPython, setuptools, etc… in Ubuntu http://stackoverflow.com/questions/6079128/compiling-python-2-6-6-and-need-for-external-packages-wxpython-setuptools-etc TARG make install # collect binary libraries ##REDO THIS IF YOU ADD ANY ADDITIONAL MODULES## function collect_binary_libs..
http://stackoverflow.com/questions/62567/ignore-case-in-python-strings libc.so.6 see link above for Win32 help libc.strcasecmp THIS this returns 0 libc.strcasecmp THIS THAT returns 8 may also.. help libc.strcasecmp THIS this returns 0 libc.strcasecmp THIS THAT returns 8 may also want to reference strcasecmp documentation..
http://stackoverflow.com/questions/8980050/persistent-python-subprocess n' p.stdout.readline 'hello world n' p.stdout.readline # THIS CALL WILL BLOCK An alternative to this method for Unix is to..
Creating a logging handler to connect to Oracle? http://stackoverflow.com/questions/935930/creating-a-logging-handler-to-connect-to-oracle # VINAY SAJIP DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING # ALL IMPLIED WARRANTIES OF MERCHANTABILITY.. OUT # OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. # # This file is part of the standalone Python logging..
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