Combining common data with inner joins

Pandas Joins for Spreadsheet Users

John Miller

Principal Data Scientist

Object-oriented expressions

$$ pandas-level function:

pd.merge(df_left, df_right, on=None)

$$

Shorthand, pandas dataframe method:

df_left.merge(df_right, on=None)
Pandas Joins for Spreadsheet Users

A basic inner join

inner join

  • Similar to VLOOKUP followed by removing NA's
df1.merge(df2, on='GameKey', how='inner')
  • Returns only rows present in both tables
Pandas Joins for Spreadsheet Users

Joining on different names

inner join with columns

  • Key columns may have different names
  • No need to rename columns
    df1.merge(df2, left_on='GameKey', right_on='game-key',
           how='inner')
Pandas Joins for Spreadsheet Users

Let's practice!

Pandas Joins for Spreadsheet Users

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