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What is a clean, pythonic way to have multiple constructors in Python?
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Actually None is much better for "magic" values:
class Cheese():
def __init__(self, num_holes = None):
if num_holes is None:
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Now if you want complete freedom of adding more parameters:
class Cheese...
Python unittest - opposite of assertRaises?
...the correct solution in fact. The solution proposed by user9876 is conceptually flawed: if you test for the non-raising of say ValueError, but ValueError is instead raised, your test must exit with a failure condition, not an error one. On the other hand, if in running the same code you would raise ...
Principal component analysis in Python
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Months later, here's a small class PCA, and a picture:
#!/usr/bin/env python
""" a small class for Principal Component Analysis
Usage:
p = PCA( A, fraction=0.90 )
In:
A: an array of e.g. 1000 observations x 20 variables, 1000 rows x 20 colum...
How can I exclude all “permission denied” messages from “find”?
I need to hide all permission denied messages from:
17 Answers
17
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What is the purpose of class methods?
...sson was that Python is not Java , and so I've just spent a while turning all my Class methods into functions.
17 Answers
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correct way to use super (argument passing)
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Shouldn't Base call super(Base, self).__init__()?
– cha0site
Jan 23 '12 at 14:47
4
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When should one use HTML entities?
...facto standard in web development I'm not sure in which situations I'm supposed to use the HTML entities and for which ones should I just use the UTF-8 character. For example,
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Delete all documents from index/type without deleting type
I know one can delete all documents from a certain type via deleteByQuery.
15 Answers
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What is the effect of extern “C” in C++?
...very compiler is required to provide "C" linkage
A linkage specification shall occur only in namespace scope
All function types, function names and variable names have a language linkage See Richard's Comment: Only function names and variable names with external linkage have a language linkage
Two ...
std::function and std::bind: what are they, and when should they be used?
...nd to get g:
auto g = bind(f, _1, 4, _2);
This is more concise than actually writing a functor class to do it.
There are further examples in the article you link to. You generally use it when you need to pass a functor to some algorithm. You have a function or functor that almost does the job yo...