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How do I make a matrix from a list of vectors in R?
...5
[8,] 8 1 2 3 4 5
[9,] 9 1 2 3 4 5
[10,] 10 1 2 3 4 5
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How does zip(*[iter(s)]*n) work in Python?
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answered Feb 9 '10 at 23:15
Ignacio Vazquez-AbramsIgnacio Vazquez-Abrams
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Generate random integers between 0 and 9
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2106
Try:
from random import randrange
print(randrange(10))
Docs: https://docs.python.org/3/librar...
How to get last items of a list in Python?
... the python CLI interpreter:
>>> a = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12]
>>> a
[1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12]
>>> a[-9:]
[4, 5, 6, 7, 8, 9, 10, 11, 12]
the important line is a[-9:]
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pandas: filter rows of DataFrame with operator chaining
...DataFrame.mask = mask
In [93]: df = pandas.DataFrame(np.random.randint(0, 10, (4,4)), index=list('abcd'), columns=list('ABCD'))
In [95]: df.ix['d','A'] = df.ix['a', 'A']
In [96]: df
Out[96]:
A B C D
a 1 4 9 1
b 4 5 0 2
c 5 5 1 0
d 1 3 9 6
In [97]: df.mask('A', 1)
Out[97]:
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recursively add file extension to all files
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edited Jul 10 '09 at 9:24
answered Jul 10 '09 at 9:14
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Pandas index column title or name
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In [8]: df.index.name = 'foo'
In [9]: df.index.name
Out[9]: 'foo'
In [10]: df
Out[10]:
Column 1
foo
Apples 1
Oranges 2
Puppies 3
Ducks 4
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Shuffle two list at once with same order
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– Jaroslav Klimčík
Apr 25 '14 at 10:15
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(noob question) - what does the * mean?
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Assign multiple columns using := in data.table, by group
... a b col1 col2 mean sum Name1 Longer%
# 1: 1 1 hi hello 2.5 5 10 15
# 2: 2 2 hi hello 3.5 7 14 21
# 3: 3 3 hi hello 4.5 9 18 27
# 4: 1 4 hi hello 2.5 5 10 15
# 5: 2 5 hi hello 3.5 7 14 21
# 6: 3 6 hi hello 4.5 9 18 27...
Regex how to match an optional character
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edited Oct 24 '10 at 7:42
answered Oct 24 '10 at 6:44
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