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Intro to Pandas: Combining DFs

Lec 9

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Objectives

  • Concat & Merge DFs

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Concat DFs

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Concat DFs

pd.concat([df1, df2], axis=0)

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The concat() function performs concatenation operations of multiple tables along one of the axis (row-wise or column-wise).

  • axis=0 (or axis='rows') is horizontal axis.
  • axis=1 (or axis='columns') is vertical axis
  • By default, concatenation is along axis 0, so the resulting table combines the rows of the input tables.

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Merge DFs

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Merge DFs

pd.merge(df1, df2,

how =’____’, on=’col’)

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  • df1: dataframe
  • df2: dataframe or series to merge with
  • how: type of merge - left (use keys from left frame), right, outer, inner
  • on: column or index level names to join on

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Resource

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Q/A break