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Python 3 ImportError: No module named 'ConfigParser'
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373
In Python 3, ConfigParser has been renamed to configparser for PEP 8 compliance. It looks like...
What regular expression will match valid international phone numbers?
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23 Answers
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Active
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Looping over a list in Python
...with sublists in it. I want to print all the sublists with length equal to 3.
4 Answers
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How can I obtain an 'unbalanced' grid of ggplots?
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73
grid.arrange draws directly on the device; if you want to combine it with other grid objects you...
List comprehension vs map
...:
$ python -mtimeit -s'xs=range(10)' 'map(hex, xs)'
100000 loops, best of 3: 4.86 usec per loop
$ python -mtimeit -s'xs=range(10)' '[hex(x) for x in xs]'
100000 loops, best of 3: 5.58 usec per loop
An example of how performance comparison gets completely reversed when map needs a lambda:
$ pytho...
What is the most efficient string concatenation method in python?
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John FouhyJohn Fouhy
35.3k1818 gold badges5757 silver badges7373 bronze badges
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Error while installing json gem 'mkmf.rb can't find header files for ruby'
...ll ruby2.0-dev
sudo apt-get install ruby2.2-dev
sudo apt-get install ruby2.3-dev
or, generic way:
sudo apt-get install ruby-dev
or
sudo apt-get install ruby`ruby -e 'puts RUBY_VERSION[/\d+\.\d+/]'`-dev
The first link you’ve posted is exactly your case: there is no ruby development...
How to filter a dictionary according to an arbitrary condition function?
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434
Nowadays, in Python 2.7 and up, you can use a dict comprehension:
{k: v for k, v in points.ite...
How to make a flat list out of list of lists?
...e the timeit module in the standard library:
$ python -mtimeit -s'l=[[1,2,3],[4,5,6], [7], [8,9]]*99' '[item for sublist in l for item in sublist]'
10000 loops, best of 3: 143 usec per loop
$ python -mtimeit -s'l=[[1,2,3],[4,5,6], [7], [8,9]]*99' 'sum(l, [])'
1000 loops, best of 3: 969 usec per loo...
Difference between float and decimal data type
...mysql> insert into numbers values (100, 100);
mysql> select @a := (a/3), @b := (b/3), @a * 3, @b * 3 from numbers \G
*************************** 1. row ***************************
@a := (a/3): 33.333333333
@b := (b/3): 33.333333333333
@a + @a + @a: 99.999999999000000000000000000000
@b + @b...