In pandas, both .join() and pd.merge() are used to combine DataFrames, but they differ in syntax, defaults, and use cases.
Merge is better than Join.
| Feature | df.join() | pd.merge() |
|---|---|---|
| Default key | Uses index of caller and index/column of other | Requires explicit column(s) to merge on |
| Syntax style | Method on a DataFrame | Function (pd.merge(left, right)) |
| Column join | Must specify on= and use one column from each | Can merge on multiple columns |
| Index join | Default behavior (index-to-index) | Requires left_index=True, right_index=True |
| Suffixes | lsuffix, rsuffix | suffixes=('_x', '_y') |
| Complex joins | Not well-suited | Supports full SQL-style joins |
| Use case | Simple joins on index or one column | Complex joins with control over join behavior |
| data_cleaningdata_integration |