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Python group by
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Python's built-in itertools module actually has a groupby function , but for that the elements to be grouped must first be sorted such that the elements to be grouped are contiguous in the list:
from operator import itemgetter
sortkeyfn = itemgetter(1)
input = [(...
How do I check if I'm running on Windows in Python? [duplicate]
...lue cannot be determined.
If that isn't working, maybe try platform.win32_ver and if it doesn't raise an exception, you're on Windows; but I don't know if that's forward compatible to 64-bit, since it has 32 in the name.
win32_ver(release='', version='', csd='', ptype='')
Get additional ...
Thread Safety in Python's dictionary
...mic operations, there are corner cases where they aren’t atomic (e.g. if __hash__ or __eq__ are implemented as Python methods) and their atomicity should not be relied upon. Neither should you rely on atomic variable assignment (since this in turn depends on dictionaries).
Use the Queue module's Q...
Why can lambdas be better optimized by the compiler than plain functions?
...assing them to a function template will instantiate a new function specifically for that object. The compiler can thus trivially inline the lambda call.
For functions, on the other hand, the old caveat applies: a function pointer gets passed to the function template, and compilers traditionally hav...
Why would finding a type's initializer throw a NullReferenceException?
....cs:
(196c.1874): Access violation - code c0000005 (first chance)
mscorlib_ni!System.RuntimeType.GetConstructorImpl(System.Reflection.BindingFlags, System.Reflection.Binder, System.Reflection.CallingConventions, System.Type[], System.Reflection.ParameterModifier[])+0xa3:
000007fe`e5735403 488b4608 ...
How can strings be concatenated?
...
The easiest way would be
Section = 'Sec_' + Section
But for efficiency, see: https://waymoot.org/home/python_string/
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Embedded MongoDB when running integration tests
...ed mongo for each test fails most of the tests. Its better to start before all the tests and shutdown once all have executed
– DBS
Apr 30 '19 at 5:36
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Replace non-ASCII characters with a single space
I need to replace all non-ASCII (\x00-\x7F) characters with a space. I'm surprised that this is not dead-easy in Python, unless I'm missing something. The following function simply removes all non-ASCII characters:
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PHP Fatal error: Cannot redeclare class
...ious repetition like this (even in quite a complex situation). The include_once tip helps to clarify an obscure feature of PHP.
– DavidHyogo
Mar 20 '13 at 2:12
2
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jQuery event to trigger action when a div is made visible
...ction($) {
var _oldShow = $.fn.show;
$.fn.show = function(speed, oldCallback) {
return $(this).each(function() {
var obj = $(this),
newCallback = function() {
if ($.isFunction(oldCallback)) {
oldCallback.apply(obj);
}
...