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Apply multiple functions to multiple groupby columns
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df
a b c d group
0 0.418500 0.030955 0.874869 0.145641 0
1 0.446069 0.901153 0.095052 0.487040 0
2 0.843026 0.936169 0.926090 0.041722 1
3 0.635846 0.439175 0.828787 0.714123 1
A dictionary mapped from column nam...
dd: How to calculate optimal blocksize? [closed]
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5 Answers
5
Active
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“is” operator behaves unexpectedly with integers
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Take a look at this:
>>> a = 256
>>> b = 256
>>> id(a)
9987148
>>> id(b)
9987148
>>> a = 257
>>> b = 257
>>> id(a)
11662816
>>> id(b)
11662828
Here's what I found in the Python 2 documentati...
How can I check whether an array is null / empty?
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Miles
27.2k77 gold badges5454 silver badges7171 bronze badges
answered Mar 3 '10 at 9:22
cletuscletus
5...
How to get last inserted id?
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For SQL Server 2005+, if there is no insert trigger, then change the insert statement (all one line, split for clarity here) to this
INSERT INTO aspnet_GameProfiles(UserId,GameId)
OUTPUT INSERTED.ID
VALUES(@UserId, @GameId)
For SQL Server ...
How do I print a double value without scientific notation using Java?
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You could use printf() with %f:
double dexp = 12345678;
System.out.printf("dexp: %f\n", dexp);
This will print dexp: 12345678.000000. If you don't want the fractional part, use
System.out.printf("dexp: %.0f\n", dexp);
This uses the format specifier language explained in...
How to jQuery clone() and change id?
...ments, retrieve highest ID
Say you have many elements with IDs like klon--5 but scrambled (not in order). Here we cannot go for :last or :first, therefore we need a mechanism to retrieve the highest ID:
const $all = $('[id^="klon--"]');
const maxID = Math.max.apply(Math, $all.map((i, el) =>...
How do you validate a URL with a regular expression in Python?
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151
An easy way to parse (and validate) URL's is the urlparse (py2, py3) module.
A regex is too ...
Running shell command and capturing the output
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1205
The answer to this question depends on the version of Python you're using. The simplest approach...
Longest line in a file
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275
Using wc (GNU coreutils) 7.4:
wc -L filename
gives:
101 filename
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