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how do I insert a column at a specific column index in pandas?
...e beginning
df.insert(loc, column, value)
df = pd.DataFrame({'B': [1, 2, 3], 'C': [4, 5, 6]})
df
Out:
B C
0 1 4
1 2 5
2 3 6
idx = 0
new_col = [7, 8, 9] # can be a list, a Series, an array or a scalar
df.insert(loc=idx, column='A', value=new_col)
df
Out:
A B C
0 7 1 4
...
Lua简明教程 - 更多技术 - 清泛网 - 专注C/C++及内核技术
...当你把他的源码下下来编译后，你会发现解释器居然不到200k，这是多么地变态啊（/bin/sh都要1M，MacOS平台），而且能和C语言非常好的互动。我很好奇得浏览了一下Lua解释器的源码，这可能是我看过最干净的C的源码了。
我不想...
Regex to validate date format dd/mm/yyyy
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20 Answers
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How can I multiply and divide using only bit shifting and adding?
...fting you want to decompose one of the numbers by powers of two, like so:
21 * 5 = 10101_2 * 101_2 (Initial step)
= 10101_2 * (1 * 2^2 + 0 * 2^1 + 1 * 2^0)
= 10101_2 * 2^2 + 10101_2 * 2^0
= 10101_2 << 2 + 10101_2 << 0 (Decomposed)
= 10101_2 *...
Mean per group in a data.frame [duplicate]
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257
This type of operation is exactly what aggregate was designed for:
d <- read.table(text=
'...
What is the optimal Jewish toenail cutting algorithm?
...le. Luckily, humans only have five toes per foot*, so there are only 5! = 120 unrestricted sequences.
Python example:
#seq is only valid when consecutive elements in the list differ by at least two.
def isValid(seq):
for i in range(len(seq)-1):
a = seq[i]
b = seq[i+1]
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How is OAuth 2 different from OAuth 1?
In very simple terms, can someone explain the difference between OAuth 2 and OAuth 1?
10 Answers
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Difference between Math.Floor() and Math.Truncate()
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12 Answers
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Mapping two integers to one, in a unique and deterministic way
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234
You're looking for a bijective NxN -> N mapping. These are used for e.g. dovetailing. Have ...