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Counting the number of elements with the values of x in a vector
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521
You can just use table():
> a <- table(numbers)
> a
numbers
4 5 23 34 43 54 ...
Deep copy of a dict in python
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502
How about:
import copy
d = { ... }
d2 = copy.deepcopy(d)
Python 2 or 3:
Python 3.2 (r32:8844...
How can I plot separate Pandas DataFrames as subplots?
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264
You can manually create the subplots with matplotlib, and then plot the dataframes on a specif...
How do I sort one vector based on values of another
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answered Oct 14 '09 at 21:47
Ian FellowsIan Fellows
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What is the most efficient way of finding all the factors of a number in Python?
...n to me an efficient way of finding all the factors of a number in Python (2.7)?
22 Answers
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What is the bower (and npm) version syntax?
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342
In a nutshell, the syntax for Bower version numbers (and NPM's) is called SemVer, which is short...
How can I check if multiplying two numbers in Java will cause an overflow?
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92
Java 8 has Math.multiplyExact, Math.addExact etc. for ints and long. These throw an unchecked Ar...
pandas: filter rows of DataFrame with operator chaining
...olean index.
In [96]: df
Out[96]:
A B C D
a 1 4 9 1
b 4 5 0 2
c 5 5 1 0
d 1 3 9 6
In [99]: df[(df.A == 1) & (df.D == 6)]
Out[99]:
A B C D
d 1 3 9 6
If you want to chain methods, you can add your own mask method and use that one.
In [90]: def mask(df, key, val...