大约有 43,500 项符合查询结果(耗时:0.0410秒) [XML]
Pandas count(distinct) equivalent
...you want:
table.groupby('YEARMONTH').CLIENTCODE.nunique()
Example:
In [2]: table
Out[2]:
CLIENTCODE YEARMONTH
0 1 201301
1 1 201301
2 2 201301
3 1 201302
4 2 201302
5 2 201302
6 3 201302
In [3...
Difference between '..' (double-dot) and '…' (triple-dot) in range generation?
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edited Dec 21 '16 at 0:33
answered Mar 13 '12 at 19:48
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How does zip(*[iter(s)]*n) work in Python?
...s to zip(), and it pulls an item from the iterator each time.
x = iter([1,2,3,4,5,6,7,8,9])
print zip(x, x, x)
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Detect URLs in text with JavaScript
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First you need a good regex that matches urls. This is hard to do. See here, here and here:
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Mod in Java produces negative numbers [duplicate]
When I calculate int i = -1 % 2 I get -1 in Java. In Python, I get 1 as the result of -1 % 2 .
What do I have to do to get the same behavior in Java with the modulo function?
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Version of SQLite used in Android?
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UPDATE OCT 2016: Here is a link to the updated official docs which includes the main points in t...
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...e): pass and while(1): pass , but this is actually not the case in python2.7.
3 Answers
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Select multiple columns in data.table by their numeric indices
...llowing all just work:
library(data.table)
dt <- data.table(a = 1, b = 2, c = 3)
# select single column by index
dt[, 2]
# b
# 1: 2
# select multiple columns by index
dt[, 2:3]
# b c
# 1: 2 3
# select single column by name
dt[, "a"]
# a
# 1: 1
# select multiple columns by name
dt[, ...