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Adding new column to existing DataFrame in Python pandas
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1091
Use the original df1 indexes to create the series:
df1['e'] = pd.Series(np.random.randn(sLeng...
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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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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How to test valid UUID/GUID?
... first character of the third block).
Therefore to validate a UUID...
/^[0-9a-f]{8}-[0-9a-f]{4}-[0-5][0-9a-f]{3}-[089ab][0-9a-f]{3}-[0-9a-f]{12}$/i
...ensures you have a canonically formatted UUID that is Version 1 through 5 and is the appropriate Variant as per RFC4122.
NOTE: Braces { and } ar...
Convert floats to ints in Pandas?
...nge(5), columns=['a'])
df.a = df.a.astype(float)
df
Out[33]:
a
0 0.0000000
1 1.0000000
2 2.0000000
3 3.0000000
4 4.0000000
pd.options.display.float_format = '{:,.0f}'.format
df
Out[35]:
a
0 0
1 1
2 2
3 3
4 4
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How to change the output color of echo in Linux
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30 Answers
30
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Set every cell in matrix to 0 if that row or column contains a 0
Given a NxN matrix with 0s and 1s. Set every row that contains a 0 to all 0 s and set every column that contains a 0 to all 0 s.
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Multiple linear regression in Python
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102
sklearn.linear_model.LinearRegression will do it:
from sklearn import linear_model
clf = linea...
Truncate Two decimal places without rounding
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value = Math.Truncate(100 * value) / 100;
Beware that fractions like these cannot be accurately represented in floating point.
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Fast permutation -> number -> permutation mapping algorithms
...ake of an example, let's say, 7 elements, 1234567. I know there are 7! = 5040 permutations possible of these 7 elements.
1...