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python Programming Glossary: asWhat is a metaclass in Python? http://stackoverflow.com/questions/100003/what-is-a-metaclass-in-python is a metaclass in Python I've mastered almost all the Python concepts well.. is a metaclass in Python I've mastered almost all the Python concepts well let's say they're just.. just OO concepts but this one is tricky. I know it has something to do with introspection but it's still unclear to..
The Python yield keyword explained http://stackoverflow.com/questions/231767/the-python-yield-keyword-explained These iterables are handy because you can read them as much as you wish but you store all the values in memory and.. iterables are handy because you can read them as much as you wish but you store all the values in memory and it's not.. set of values that you will only need to read once. To master yield you must understand that when you call the function..
What is a metaclass in Python? http://stackoverflow.com/questions/100003/what-is-a-metaclass-in-python than that in Python. Classes are objects too. Yes objects. As soon as you use the keyword class Python executes it and creates..
How to install MySQLdb (Python data access library to MySQL) on Mac OS X? http://stackoverflow.com/questions/1448429/how-to-install-mysqldb-python-data-access-library-to-mysql-on-mac-os-x .. out of build directory and the error should disappear. As I wrote at the top I'd love to see this answer generalised as..
How does zip(*[iter(s)]*n) work in Python? http://stackoverflow.com/questions/2233204/how-does-zipitersn-work-in-python explain well the roles of argument unpacking and zip . As Ignacio and ujukatzel say you pass to zip three identical iterators..
http://stackoverflow.com/questions/233673/lexical-closures-in-python because it causes an error for f in flist print f 2 As the commented line shows i is unknown at that point. Still it..
Is False == 0 and True == 1 in Python an implementation detail or is it guaranteed by the language? http://stackoverflow.com/questions/2764017/is-false-0-and-true-1-in-python-an-implementation-detail-or-is-it-guarante appreciated Other comments would be appreciated too Edit As noted in many answers bool inherits from int . The question..
Import a module from a relative path http://stackoverflow.com/questions/279237/import-a-module-from-a-relative-path path python import share improve this question Assuming that both your directories are real python packages do.. also fails because it doesn't not always contains the path As a bonus this approach does let you force Python to use your..
Calling a function from a string with the function's name in Python http://stackoverflow.com/questions/3061/calling-a-function-from-a-string-with-the-functions-name-in-python way to do this. python share improve this question Assuming module foo with method bar import foo methodToCall getattr.. foo methodToCall getattr foo 'bar' result methodToCall As far as that goes lines 2 and 3 can be compressed to result getattr..
Is there any way to kill a Thread in Python? http://stackoverflow.com/questions/323972/is-there-any-way-to-kill-a-thread-in-python raised not instances res ctypes.pythonapi.PyThreadState_SetAsyncExc tid ctypes.py_object exctype if res 0 raise ValueError.. to revert the effect ctypes.pythonapi.PyThreadState_SetAsyncExc tid 0 raise SystemError PyThreadState_SetAsyncExc failed.. tid 0 raise SystemError PyThreadState_SetAsyncExc failed class ThreadWithExc threading.Thread '''A thread..
*args and **kwargs? [duplicate] http://stackoverflow.com/questions/3394835/args-and-kwargs 'cat' print_three_things mylist a aardvark b baboon c cat As you can see in this case it takes the list or tuple of items..
Python variable scope question http://stackoverflow.com/questions/370357/python-variable-scope-question global c put global c as the first line of the function. As of python 3 there is now nonlocal c that you can use to refer..
Flattening a shallow list in Python http://stackoverflow.com/questions/406121/flattening-a-shallow-list-in-python when you extend the original with the temporary. Edit As J.F. Sebastian says itertools.chain.from_iterable avoids the..
Python: Is there a way to determine the encoding of text file? http://stackoverflow.com/questions/436220/python-is-there-a-way-to-determine-the-encoding-of-text-file to determine text file encoding Thanks for your help Edit As a side question it can be ignored if you want but why is the..
How do I unload (reload) a Python module? http://stackoverflow.com/questions/437589/how-do-i-unload-reload-a-python-module function of extension modules is not called a second time. As with all other objects in Python the old objects are only reclaimed.. in each namespace where they occur if that is desired. As you noted in your question you'll have to reconstruct Foo objects..
Static class variables in Python http://stackoverflow.com/questions/68645/static-class-variables-in-python or static variables class MyClass ... i 3 ... MyClass.i 3 As @Daniel points out this creates a class level i variable but..
http://stackoverflow.com/questions/7933596/django-dynamic-model-fields django custom manager share improve this question As of today there are four available approaches two of them requiring..
Why is reading lines from stdin much slower in C++ than Python? http://stackoverflow.com/questions/9371238/why-is-reading-lines-from-stdin-much-slower-in-c-than-python greatly appreciated by posterity. Edit 5 Better Solution As suggested by Gandalf The Gray below gets is even faster than.. 428 cin no sync 12 500 000 fgets 14 285 714 wc 54 644 808 As you can see fgets is better but still pretty far from wc performance.. Thanks to all for your comments and suggestions. Edit 6 As suggested by J.F. Sebastian in the comments below the GNU wc..
Python: How do I pass a variable by reference? http://stackoverflow.com/questions/986006/python-how-do-i-pass-a-variable-by-reference reference . Let's work on that. How do we get around this As @Andrea's answer shows you could return the new value. This..
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 # distributed under the License is distributed on an AS IS BASIS # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND either.. distributed under the License is distributed on an AS IS BASIS # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND either express.. def valid_resident resident return USER_RE.match resident PASS_RE re.compile r ^. 3 20 def valid_SSN SSN return PASS_RE.match..
How to query GAE datastore to render a template (newbie level) http://stackoverflow.com/questions/11311461/how-to-query-gae-datastore-to-render-a-template-newbie-level # distributed under the License is distributed on an AS IS BASIS # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND either.. distributed under the License is distributed on an AS IS BASIS # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND either express.. 3 20 def valid_person person return USER_RE.match person PASS_RE re.compile r ^. 3 20 def valid_SSN SSN return PASS_RE.match..
Python with MS SQL - truncated output http://stackoverflow.com/questions/11882910/python-with-ms-sql-truncated-output to our system. SQL sql ''' SELECT Req.ID ShReq.Summary AS Short Name ShReq.ALM_SharedText AS Text Req.ContainedBy Req.DocumentID.. Req.ID ShReq.Summary AS Short Name ShReq.ALM_SharedText AS Text Req.ContainedBy Req.DocumentID FROM CurMKS..ALM_Requirement.. using conversions like convert text ShReq.ALM_SharedText AS TEXT and CAST ShReq.ALM_SharedText AS TEXT I increase truncating..
http://stackoverflow.com/questions/11957925/psycopg2-mapping-python-list-of-dicts-to-postgres-array-of-composite-type I have the following Schema DROP TABLE IF EXISTS posts CASCADE DROP TYPE IF EXISTS quotes CASCADE CREATE TYPE quotes AS.. TABLE IF EXISTS posts CASCADE DROP TYPE IF EXISTS quotes CASCADE CREATE TYPE quotes AS text CHARACTER VARYING is_direct CHARACTER.. DROP TYPE IF EXISTS quotes CASCADE CREATE TYPE quotes AS text CHARACTER VARYING is_direct CHARACTER VARYING CREATE TABLE..
Use lxml to parse text file with bad header in Python http://stackoverflow.com/questions/12412994/use-lxml-to-parse-text-file-with-bad-header-in-python DOCUMENT COUNT 7 CONFORMED PERIOD OF REPORT 20070630 FILED AS OF DATE 20070913 DATE AS OF CHANGE 20070913 and the first isn't.. PERIOD OF REPORT 20070630 FILED AS OF DATE 20070913 DATE AS OF CHANGE 20070913 and the first isn't until line 51 in this..
matplotlib: how to prevent x-axis labels from overlapping each other http://stackoverflow.com/questions/13515471/matplotlib-how-to-prevent-x-axis-labels-from-overlapping-each-other day the db has an entry. SELECT to_char s.day 'yyyymm' AS month count t.id int AS count FROM SELECT generate_series min.. SELECT to_char s.day 'yyyymm' AS month count t.id int AS count FROM SELECT generate_series min date_from date max date_from.. date_from date max date_from date interval '1 day' date AS day FROM mytable t s LEFT JOIN mytable t ON t.date_from date..
http://stackoverflow.com/questions/13893287/python-time-limit NOT STOP UNTIL IT FINISHES AND WE DISCOVER THAT WE ARE PAST OUR DEADLINE. THE TASK NEEDS TO BE INTERRUPTED IN PROGRESS.. AND WE DISCOVER THAT WE ARE PAST OUR DEADLINE. THE TASK NEEDS TO BE INTERRUPTED IN PROGRESS AS SOON AS THE TIME ELAPSES... OUR DEADLINE. THE TASK NEEDS TO BE INTERRUPTED IN PROGRESS AS SOON AS THE TIME ELAPSES. max_time 30 start_time time.time #..
http://stackoverflow.com/questions/15275055/data-validation-python-2-7 is the code that I have edited so far for the upcoming AS computing Preliminary code. It's homework and I am stuck as..
Filter zipcodes by proximity in Django with the Spherical Law of Cosines http://stackoverflow.com/questions/1916953/filter-zipcodes-by-proximity-in-django-with-the-spherical-law-of-cosines cos radians lng radians 122 sin radians 37 sin radians lat AS distance FROM stores HAVING distance 25 ORDER BY distance LIMIT.. radians lng radians 122 sin radians 37 sin radians lat AS distance FROM stores HAVING distance 25 ORDER BY distance LIMIT..
http://stackoverflow.com/questions/2317452/django-count-rawqueryset s PI 180 COS lat PI 180 COS s lon PI 180 180 PI 60 1.1515 AS distance FROM app_car WHERE price BETWEEN s AND s HAVING distance.. price BETWEEN s AND s HAVING distance s ORDER BY distance ASC cars Car.objects.raw query lat lat lon min_price max_price.. s PI 180 COS lat PI 180 COS s lon PI 180 180 PI 60 1.1515 AS distance FROM app_car WHERE price BETWEEN s AND s HAVING distance..
How do I escape % from python mysql query http://stackoverflow.com/questions/3037581/how-do-i-escape-from-python-mysql-query For example query SELECT DATE_FORMAT date_time ' Y m' AS dd FROM some_table WHERE some_col s AND other_col s cur.execute..
Why are scripting languages (e.g. Perl, Python, Ruby) not suitable as shell languages? [closed] http://stackoverflow.com/questions/3637668/why-are-scripting-languages-e-g-perl-python-ruby-not-suitable-as-shell-lang Language CL as prior art. For anyone who has ever used an AS 400 this should sound familiar. In OS 400 you can write a shell..
Optimizing performance of Postgresql database writes in Django? http://stackoverflow.com/questions/9423539/optimizing-performance-of-postgresql-database-writes-in-django the structure of an existing table CREATE TEMP TABLE tmp_x AS SELECT FROM tbl LIMIT 0 Copy values should take seconds not..
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