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[] and {} vs list() and dict(), which is better?
...
In terms of speed, it's no competition for empty lists/dicts:
>>> from timeit import timeit
>>> timeit("[]")
0.040084982867934334
>>> timeit("list()")
0.17704233359267718
>>> timeit("{}")
0.033620194745424214
>>> timeit("dict()")
0.18215583265...
Reset keys of array elements in php?
...he simple array_values approach:
The Array:
$array['a'][0] = array('x' => 1, 'y' => 2, 'z' => 3);
$array['a'][5] = array('x' => 4, 'y' => 5, 'z' => 6);
$array['b'][1] = array('x' => 7, 'y' => 8, 'z' => 9);
$array['b'][7] = array('x' => 10, 'y' => 11, 'z' => 12)...
+ operator for array in PHP?
...l be ignored.
So if you do
$array1 = ['one', 'two', 'foo' => 'bar'];
$array2 = ['three', 'four', 'five', 'foo' => 'baz'];
print_r($array1 + $array2);
You will get
Array
(
[0] => one // preserved from $array1 (left-hand array)
[1] => two // preserved from $...
How can I use tabs for indentation in IntelliJ IDEA?
... for the current file
You have the following options:
Ctrl + Shift + A > write "tabs" > double click on "To Tabs"
If you want to convert tabs to spaces, you can write "spaces", then choose "To Spaces".
Edit > Convert Indents > To Tabs
To convert tabs to spaces, you can chose "To S...
Random string generation with upper case letters and digits
...or _ in range(N))
In details, with a clean function for further reuse:
>>> import string
>>> import random
>>> def id_generator(size=6, chars=string.ascii_uppercase + string.digits):
... return ''.join(random.choice(chars) for _ in range(size))
...
>>> id_ge...
How to deep copy a list?
...py operation on arbitrary Python objects.
See the following snippet -
>>> a = [[1, 2, 3], [4, 5, 6]]
>>> b = list(a)
>>> a
[[1, 2, 3], [4, 5, 6]]
>>> b
[[1, 2, 3], [4, 5, 6]]
>>> a[0][1] = 10
>>> a
[[1, 10, 3], [4, 5, 6]]
>>> b # b...
Resharper Alt Enter not working
...pply Visual Studio keyboard scheme:
(VS2013 latest ReSharper) ReSharper > Options > Environment > Keyboard & Menus > ReSharper Platform keyboard scheme: Visual Studio > Apply Scheme > Save. This will reset the shortcut keys for ReSharper.
(older versions) ReSharper > Optio...
What is the best way to compute trending topics or tags?
...)
# Zscore Calculation.
return (obs - avg) / std
Sample Output
>>> zscore(12, [2, 4, 4, 4, 5, 5, 7, 9])
3.5
>>> zscore(20, [21, 22, 19, 18, 17, 22, 20, 20])
0.0739221270955
>>> zscore(20, [21, 22, 19, 18, 17, 22, 20, 20, 1, 2, 3, 1, 2, 1, 0, 1])
1.00303599234
&g...
Finding differences between elements of a list
...
>>> t
[1, 3, 6]
>>> [j-i for i, j in zip(t[:-1], t[1:])] # or use itertools.izip in py2k
[2, 3]
share
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...
numpy matrix vector multiplication [duplicate]
...implest solution
Use numpy.dot or a.dot(b). See the documentation here.
>>> a = np.array([[ 5, 1 ,3],
[ 1, 1 ,1],
[ 1, 2 ,1]])
>>> b = np.array([1, 2, 3])
>>> print a.dot(b)
array([16, 6, 8])
This occurs because numpy arrays are no...