pandas drop_duplicates unhashable type: 'numpy.ndarray', 'set' and 'list'

问题:

I am trying to use drop_duplicates on a column of a dataframe,

A          len ['1', '2'] 2 ['1', '2'] 2 ['3']      1 ['4', '5'] 2  ['4', '5'] 2 

The result dataframe should look like

A          len ['1', '2'] 2 ['3']      1 ['4', '5'] 2  

I have tried df.drop_duplicates('A', inplace=True), but got error,

unhashable type: 'numpy.ndarray' 

I have also converted A to lists and sets using df['A'].apply(list) and df['A'].apply(set), and then using drop_duplicates, but all failed with unhashable type: 'set' and 'list'. I am wondering how to resolve the issue.

回答1:

You need tuple:

df['A'].apply(tuple) 

So use duplicated with boolean indexing:

df = df[~df['A'].apply(tuple).duplicated()] print (df)         A  len 0  [1, 2]    2 2     [3]    1 3  [4, 5]    2 

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