Guided Notes
Merging & Joining
Combining DataFrames with concat, merge on keys, join types, and checking results.
Two ways to combine tables
Slide 1 / 5• pd.concat stacks DataFrames — adding rows (like appending January's and February's sales) or, with axis=1, placing them side by side. • pd.merge joins DataFrames on matching key columns — like SQL's JOIN, bringing customer names into an orders table.
Use concat when the tables have the same columns; use merge when they share a key but hold different information.