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
Are there any code examples left?
New code examples in category Python
-
Python 2023-04-11 03:04:20
-
Python 2022-03-27 22:40:04 pycharm no module named
-
Python 2022-03-27 22:25:05 assign multiple variablesin one line
-
Python 2022-03-27 22:20:02 levenshtein distance
-
Python 2022-03-27 21:35:09 get text from url python last slash
-
Python 2022-03-27 21:30:30 df concatenate df
-
Python 2022-03-27 21:25:09 python odd or even
-
Python 2022-03-27 21:15:32 python include function from another file
-
Python 2022-03-27 21:10:01 color module python
-
Python 2022-03-27 21:00:27 python tkinter cursor types