Questions tagged [bodo]
3 questions
87
votes
8 answers
Parallelize apply after pandas groupby
I have used rosetta.parallel.pandas_easy to parallelize apply after groupby, for example:
from rosetta.parallel.pandas_easy import groupby_to_series_to_frame
df = pd.DataFrame({'a': [6, 2, 2], 'b': [4, 5, 6]},index= ['g1', 'g1',…
Ivan
- 2,871
- 3
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6
votes
3 answers
pandas: groupby apply using numba
Using pandas v1.1.0.
In the pandas docs there is a nice example on how to use numba to speed up a rolling.apply() operation here
import pandas as pd
import numpy as np
def mad(x):
return np.fabs(x - x.mean()).mean()
df = pd.DataFrame({"A":…
Ray Bell
- 1,508
- 4
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- 45
2
votes
3 answers
Speeding up group-wise differencing in Pandas
Consider the following solution to computing a within-group diff in Pandas:
df = df.set_index(['ticker', 'date']).sort_index()[['value']]
df['diff'] = np.nan
idx = pd.IndexSlice
for ix in df.index.levels[0]:
df.loc[ idx[ix,:], 'diff'] =…
Amelio Vazquez-Reina
- 91,494
- 132
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