Data Science
Aggregations in Pandas (GROUP BY)
Senior Data Analyst
April 17, 2026
6 min read
Simple Aggregations
df['price'].sum()
df['price'].mean()
df['price'].count()
df['price'].max()
GROUP BY
df.groupby('category')['price'].sum()
df.groupby('category').agg({'price': 'sum', 'quantity': 'mean'})
Multiple Aggregations
df.groupby('category').agg(
total_revenue=('price', 'sum'),
avg_price=('price', 'mean'),
order_count=('order_id', 'count')
)
*Day 108: Merging DataFrames (JOINs).*