Data Science
Scaling and Normalization
Senior Data Analyst
May 4, 2026
5 min read
Why Scale?
If `age` ranges 0-100 and `income` ranges 0-1,000,000, the model will be biased toward income.
Standard Scaling (Z-Score)
from sklearn.preprocessing import StandardScaler
scaler = StandardScaler()
df[['age', 'income']] = scaler.fit_transform(df[['age', 'income']])
Min-Max Scaling (0-1)
from sklearn.preprocessing import MinMaxScaler
scaler = MinMaxScaler()
df[['age', 'income']] = scaler.fit_transform(df[['age', 'income']])
*Day 125: Introduction to Machine Learning.*