pandas
The standard Python library for tabular and time-series data analysis.
- DataFrame + Series built on NumPy.
- Rich I/O: CSV, Parquet, JSON, SQL.
- pandas 2.x adds PyArrow backends.
When to use: EDA, feature engineering, any tabular ML preprocessing.
Example: df = pd.read_csv("loans.csv"); df.groupby("region")["amount"].mean().