Introduction to Pandas

Pandas' two core objects are the Series (a single labeled column of data) and the DataFrame (a table made of multiple Series sharing the same index) — think of a DataFrame as a spreadsheet you can manipulate in code.

`df.head()` previews the first few rows; `df["column"]` selects one column; `df[df["age"] > 30]` filters rows by a condition — very similar in spirit to a SQL WHERE clause.

Real-world data is messy — pandas' most-used methods (`dropna`, `fillna`, `groupby`) exist specifically to clean and summarize imperfect data before analysis.