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One-liner to check whether an iterator yields at least one element?
... Similarly if you need to check if the iterator is empty, one could use all(False for _ in iterator) will check if the iterator is empty. (all returns True if the iterator is empty, otherwise it stops when it sees the first False element)
– KGardevoir
Apr 3 ...
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:
...
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...
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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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...
jQuery find events handlers registered with an object
..."
$.each(event, function(j, h) {
// h.handler is the function being called
});
});
Here's an example you can play with:
$(function() {
$("#el").click(function(){ alert("click"); });
$("#el").mouseover(function(){ alert("mouseover"); });
$.each($._data($("#el")[0], "events")...