/Python/Expand pandas dataframe into separate rows

Expand pandas dataframe into separate rows

def explode(df, lst_cols, fill_value='', preserve_index=False):
    # make sure `lst_cols` is list-alike
    if (lst_cols is not None
        and len(lst_cols) > 0
        and not isinstance(lst_cols, (list, tuple, np.ndarray, pd.Series))):
        lst_cols = [lst_cols]
    # all columns except `lst_cols`
    idx_cols = df.columns.difference(lst_cols)
    # calculate lengths of lists
    lens = df[lst_cols[0]].str.len()
    # preserve original index values    
    idx = np.repeat(df.index.values, lens)
    # create "exploded" DF
    res = (pd.DataFrame({
                col:np.repeat(df[col].values, lens)
                for col in idx_cols},
                index=idx)
             .assign(**{col:np.concatenate(df.loc[lens>0, col].values)
                            for col in lst_cols}))
    # append those rows that have empty lists
    if (lens == 0).any():
        # at least one list in cells is empty
        res = (res.append(df.loc[lens==0, idx_cols], sort=False)
                  .fillna(fill_value))
    # revert the original index order
    res = res.sort_index()
    # reset index if requested
    if not preserve_index:        
        res = res.reset_index(drop=True)
    return res

Source: stackoverflow.com

Similar codes

0 vote328 views1 answer
Np array blurring
Python
1 vote311 views1 answer
How to close python with a line of code
Python
29 votes317 views2 answers
Python string upper method
Python
3 votes310 views2 answers
Change django administration title
Python
1 vote314 views1 answer
Python append several values
Python
0 vote328 views1 answer
Bytearray to hex python
Python
18 votes334 views3 answers
Export flask app
Python
2 votes320 views2 answers
Likeliness python
Python
0 vote343 views1 answer
How to capitalize every item in a list python
Python
26 votes326 views1 answer
Dictionary from two lists
Python