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Drop rows with all zeros in pandas data frame
...ere an equivalent function for dropping rows with all columns having value 0?
12 Answers
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Mapping two integers to one, in a unique and deterministic way
...sy to define a bijection f : Z -> N, like so:
f(n) = n * 2 if n >= 0
f(n) = -n * 2 - 1 if n < 0
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Pandas groupby: How to get a union of strings
..._csv(StringIO(data),sep='\s+')
In [5]: df
Out[5]:
A B C
0 1 0.749065 This
1 2 0.301084 is
2 3 0.463468 a
3 4 0.643961 random
4 1 0.866521 string
5 2 0.120737 !
In [6]: df.dtypes
Out[6]:
A int64
B float64
C object
dtype: object
When...
Shortest distance between a point and a line segment
...at l2 = length_squared(v, w); // i.e. |w-v|^2 - avoid a sqrt
if (l2 == 0.0) return distance(p, v); // v == w case
// Consider the line extending the segment, parameterized as v + t (w - v).
// We find projection of point p onto the line.
// It falls where t = [(p-v) . (w-v)] / |w-v|^2
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Simple C example of doing an HTTP POST and consuming the response
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+50
A message has a header part and a message body separated by a blank line. The blank line is ALWAYS needed even if there is no message...
Multiple linear regression in Python
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102
sklearn.linear_model.LinearRegression will do it:
from sklearn import linear_model
clf = linea...
How to select rows with one or more nulls from a pandas DataFrame without listing columns explicitly
I have a dataframe with ~300K rows and ~40 columns.
I want to find out if any rows contain null values - and put these 'null'-rows into a separate dataframe so that I could explore them easily.
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Formula to determine brightness of RGB color
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20 Answers
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Vagrant reverse port forwarding?
...ROR -o IdentitiesOnly=yes -i ~/.vagrant.d/insecure_private_key vagrant@127.0.0.1
SSH supports forwarding ports in the direction you want with the -R guestport:host:hostport option. So, if you wanted to connect to port 12345 on the guest and have it forwarded to localhost:80, you would use this comm...
Pandas index column title or name
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In [8]: df.index.name = 'foo'
In [9]: df.index.name
Out[9]: 'foo'
In [10]: df
Out[10]:
Column 1
foo
Apples 1
Oranges 2
Puppies 3
Ducks 4
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