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How to use a custom comparison function in Python 3?

...ert your old cmp function to a key function). functools has a function cmp_to_key mentioned at docs.python.org/3.6/library/functools.html#functools.cmp_to_key share | improve this answer |...
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Get names of all keys in the collection

...You could do this with MapReduce: mr = db.runCommand({ "mapreduce" : "my_collection", "map" : function() { for (var key in this) { emit(key, null); } }, "reduce" : function(key, stuff) { return null; }, "out": "my_collection" + "_keys" }) Then run distinct on the resulting collecti...
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How could I use requests in asyncio?

...r any other blocking libraries) with asyncio, you can use BaseEventLoop.run_in_executor to run a function in another thread and yield from it to get the result. For example: import asyncio import requests @asyncio.coroutine def main(): loop = asyncio.get_event_loop() future1 = loop.run_in_...
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Why does Windows64 use a different calling convention from all other OSes on x86-64?

...ion encoding (the MOD R/M byte, see http://www.c-jump.com/CIS77/CPU/x86/X77_0060_mod_reg_r_m_byte.htm), register numbers 0...7 are - in that order - ?AX, ?CX, ?DX, ?BX, ?SP, ?BP, ?SI, ?DI. Hence choosing A/C/D (regs 0..2) for return value and the first two arguments (which is the "classical" 32bit _...
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is there a css hack for safari only NOT chrome?

...ort term issues. The test site: https://browserstrangeness.bitbucket.io/css_hacks.html#safari AND MIRROR! https://browserstrangeness.github.io/css_hacks.html#safari NOTE: Filters and compilers (such as the SASS engine) expect standard 'cross-browser' code -- NOT CSS hacks like these which means they...
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“is” operator behaves unexpectedly with integers

...tively rare. Here's an example (will work in Python 2 and 3) e.g. SENTINEL_SINGLETON = object() # this will only be created one time. def foo(keyword_argument=None): if keyword_argument is None: print('no argument given to foo') bar() bar(keyword_argument) bar('baz') def b...
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How to round a number to significant figures in Python

...t digit: >>> from math import log10, floor >>> def round_to_1(x): ... return round(x, -int(floor(log10(abs(x))))) ... >>> round_to_1(0.0232) 0.02 >>> round_to_1(1234243) 1000000.0 >>> round_to_1(13) 10.0 >>> round_to_1(4) 4.0 >>> rou...
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Writing a Python list of lists to a csv file

...s pd In [2]: a = [[1.2,'abc',3],[1.2,'werew',4],[1.4,'qew',2]] In [3]: my_df = pd.DataFrame(a) In [4]: my_df.to_csv('my_csv.csv', index=False, header=False) share | improve this answer ...
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Adding new column to existing DataFrame in Python pandas

...17438 0.847941 0.034235 -0.448948 2.228131 >>> p.version.short_version '0.16.1' The SettingWithCopyWarning aims to inform of a possibly invalid assignment on a copy of the Dataframe. It doesn't necessarily say you did it wrong (it can trigger false positives) but from 0.13.0 it let yo...
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How do I list all tables in a schema in Oracle SQL?

...BA role. With any of those, you can select: SELECT DISTINCT OWNER, OBJECT_NAME FROM DBA_OBJECTS WHERE OBJECT_TYPE = 'TABLE' AND OWNER = '[some other schema]' Without those system privileges, you can only see tables you have been granted some level of access to, whether directly or through...