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Referring to the null object in Python
...
SyntaxError: cannot assign to keyword
It's therefore safe to assume that all None references are the same. There isn't any "custom" None.
To test for None use the is operator
When writing code you might be tempted to test for Noneness like this:
if value==None:
pass
Or to test for falsehood l...
Chain-calling parent initialisers in python [duplicate]
... B inheriting from A, class C inheriting from B. What is a generic way to call a parent class initialiser in an initialiser? If this still sounds too vague, here's some code.
...
How to automatically generate N “distinct” colors?
I wrote the two methods below to automatically select N distinct colors. It works by defining a piecewise linear function on the RGB cube. The benefit of this is you can also get a progressive scale if that's what you want, but when N gets large the colors can start to look similar. I can also imagi...
What's the difference between SortedList and SortedDictionary?
...<TKey,TValue> ? Are there any circumstances where you would specifically use one and not the other?
7 Answers
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Use cases for the 'setdefault' dict method
...e case: Grouping items (in unsorted data, else use itertools.groupby)
# really verbose
new = {}
for (key, value) in data:
if key in new:
new[key].append( value )
else:
new[key] = [value]
# easy with setdefault
new = {}
for (key, value) in data:
group = new.setdefault(k...
Underscore prefix for property and method names in JavaScript
...
Welcome to 2019!
It appears a proposal to extend class syntax to allow for # prefixed variable to be private was accepted. Chrome 74 ships with this support.
_ prefixed variable names are considered private by convention but are still public.
This syntax tries to be both terse and int...
How do I change the working directory in Python?
...If the exception is thrown, do not perform any recursive operations, especially destructive ones. They will operate on the old path and not the new one.
Return to your old directory when you're done. This can be done in an exception-safe manner by wrapping your chdir call in a context manager, lik...
django urls without a trailing slash do not redirect
...ost.". "The APPEND_SLASH setting is only used if CommonMiddleware is installed...". I prefer Michael Gendin's answer for a cleaner solution.
– Wtower
Feb 11 '15 at 9:26
...
File Upload ASP.NET MVC 3.0
...maxRequestLength="x" /> in your web.config, where x is the number of KB allowed for upload.
– rsbarro
May 22 '11 at 20:33
86
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What tools are there for functional programming in C?
...ing in C ( not C++). Obviously, C is a procedural language and doesn't really support functional programming natively.
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