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Logical operators for boolean indexing in Pandas
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unutbuunutbu
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What does this square bracket and parenthesis bracket notation mean [first1,last1)?
...1 (and includes it), but ends just before last1.
Assuming integers:
(0, 5) = 1, 2, 3, 4
(0, 5] = 1, 2, 3, 4, 5
[0, 5) = 0, 1, 2, 3, 4
[0, 5] = 0, 1, 2, 3, 4, 5
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How do you split a list into evenly sized chunks?
... yield lst[i:i + n]
import pprint
pprint.pprint(list(chunks(range(10, 75), 10)))
[[10, 11, 12, 13, 14, 15, 16, 17, 18, 19],
[20, 21, 22, 23, 24, 25, 26, 27, 28, 29],
[30, 31, 32, 33, 34, 35, 36, 37, 38, 39],
[40, 41, 42, 43, 44, 45, 46, 47, 48, 49],
[50, 51, 52, 53, 54, 55, 56, 57, 58, 59],
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Pandas dataframe get first row of each group
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Counting the occurrences / frequency of array elements
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edited Jan 10 '19 at 22:56
jpaugh
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Replace values in list using Python [duplicate]
...e if you want, but it doesn't actually save time:
items = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
for index, item in enumerate(items):
if not (item % 2):
items[index] = None
Here are (Python 3.6.3) timings demonstrating the non-timesave:
In [1]: %%timeit
...: items = [0, 1, 2, 3, 4, 5,...
Regex how to match an optional character
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256
Use
[A-Z]?
to make the letter optional. {1} is redundant. (Of course you could also write [A...
Sort rows in data.table in decreasing order on string key `order(-x,v)` gives error on data.table 1.
...n use DT[order(-rank(x), y)].
x y v
1: c 1 7
2: c 3 8
3: c 6 9
4: b 1 1
5: b 3 2
6: b 6 3
7: a 1 4
8: a 3 5
9: a 6 6
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What is :: (double colon) in Python when subscripting sequences?
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257
it means 'nothing for the first argument, nothing for the second, and jump by three'. It gets e...
Difference between '..' (double-dot) and '…' (triple-dot) in range generation?
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