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Python creating a dictionary of lists
...s import defaultdict
>>> d = defaultdict(list)
>>> a = ['1', '2']
>>> for i in a:
... for j in range(int(i), int(i) + 2):
... d[j].append(i)
...
>>> d
defaultdict(<type 'list'>, {1: ['1'], 2: ['1', '2'], 3: ['2']})
>>> d.items()
[(1, ['1']), (...
Calculating frames per second in a game
...
19 Answers
19
Active
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Convert Year/Month/Day to Day of Year in Python
...
261
There is a very simple solution:
from datetime import datetime
day_of_year = datetime.now().tim...
How to return a part of an array in Ruby?
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195
Yes, Ruby has very similar array-slicing syntax to Python. Here is the ri documentation for th...
Bundler: Command not found
I am hosting on a vps, ubuntu 10.04, rails 3, ruby and mysql installed correctly by following some tutorials. If I run bundle check or bundle install I get the error '-bash: bundle: command not found'. From gem list --local I see 'bundler (1.0.2, 1.0.0)' is installed.
...
How to find the installed pandas version
...sion__:
In [76]: import pandas as pd
In [77]: pd.__version__
Out[77]: '0.12.0-933-g281dc4e'
Pandas also provides a utility function, pd.show_versions(), which reports the version of its dependencies as well:
In [53]: pd.show_versions(as_json=False)
INSTALLED VERSIONS
------------------
commit:...
Real life example, when to use OUTER / CROSS APPLY in SQL
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175
Some uses for APPLY are...
1) Top N per group queries (can be more efficient for some cardina...
Why is 1/1/1970 the “epoch time”?
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Early versions of unix measured system time in 1/60 s intervals. This meant that a 32-bit unsigned integer could only represent a span of time less than 829 days. For this reason, the time represented by the number 0 (called the epoch) had to be set in the very recent pas...
How to use a decimal range() step value?
Is there a way to step between 0 and 1 by 0.1?
33 Answers
33
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