pandas-cheat-sheet.md

Pandas cheat sheet

Because I always forget how to do the same things, over and over again

See also: R stats cheat sheet

Helpful links:

• Pandas and R comparison

Split-Apply-Combine type stuff

Count instances of variables within groups

df.value_counts(subset=['county', 'category']).to_frame(name='n').reset_index()

Mutate a grouped data frame

df['pct'] = df['n'] / df.groupby('county')['n'].transform('sum')

Dataframe tips

Sort by columns

df.sort_values(['col1', 'col2'])
df.sort_values('col1', ascending=False)
df.sort_values(['col1', 'col2'], ascending=[True, False])

Jupyter tips

Show all rows/columns of a dataframe

with pd.option_context('display.max_rows', None, 'display.max_columns', None):
    display(df)

Convert a series to a dataframe for better printing

series.to_frame(name'col_name')