Pivot Tables and Crosstabulations

Pivot Tables

pivot_table reshapes data, aggregating values across two dimensions.

Simple pivot

sales = pd.read_csv('sales.csv')
# Total revenue per store per month
pivot = sales.pivot_table(values='revenue', index='store_id', columns='month', aggfunc='sum', fill_value=0)
print(pivot)

Multiple aggregation functions

pivot_multi = sales.pivot_table(values='units', index='store_id', columns='product_category', aggfunc=['sum', 'mean'], fill_value=0)
print(pivot_multi)

Using crosstab

# Cross tab of gender vs. purchased product
tab = pd.crosstab(df['gender'], df['product'])
print(tab)

Adding margins (totals)

pivot = sales.pivot_table(values='revenue', index='store_id', columns='month', aggfunc='sum', margins=True)
print(pivot)