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Multiple aggregations of the same column using pandas GroupBy.agg()
Is there a pandas built-in way to apply two different aggregating functions f1, f2 to the same column df["returns"] , without having to call agg() multiple times?
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Why does ~True result in -2?
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int(True) is 1.
1 is:
00000001
and ~1 is:
11111110
Which is -2 in Two's complement1
1 Flip all the bits, add 1 to the resulting number and interpret the result as a binary representation of the magnitude and add a negative sign (since the number begins...
Java packages com and org
What are the meaning of the packages org and com in Java?
4 Answers
4
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Can I set an opacity only to the background image of a div?
...nnot be done since opacity affects the whole element including its content and there's no way to alter this behavior. You can work around this with the two following methods.
Secondary div
Add another div element to the container to hold the background. This is the most cross-browser friendly meth...
“ValueError: zero length field name in format” error in Python 3.0,3.1,3.2
I'm trying learn Python (3 to be more specific) and I'm getting this error:
3 Answers
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Access denied for user 'root@localhost' (using password:NO)
I'm new to MySQL, I'm trying to run WordPress in my Windows desktop and it needs MySQL.
16 Answers
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Is there a performance difference between i++ and ++i in C++?
We have the question is there a performance difference between i++ and ++i in C?
17 Answers
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Convert character to ASCII code in JavaScript
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@MathiasBynens: and fortunately this is documented: developer.mozilla.org/en/JavaScript/Reference/Global_Objects/…. "if it is not a number, it defaults to 0"
– tokland
Nov 15 '11 at 19:46
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How can I apply a function to every row/column of a matrix in MATLAB?
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Many built-in operations like sum and prod are already able to operate across rows or columns, so you may be able to refactor the function you are applying to take advantage of this.
If that's not a viable option, one way to do it is to collect the rows or c...
Understanding exactly when a data.table is a reference to (vs a copy of) another data.table
I'm having a little trouble understanding the pass-by-reference properties of data.table . Some operations seem to 'break' the reference, and I'd like to understand exactly what's happening.
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