repeating the rows of a data frame

Question

I\'m trying repeat the rows of a dataframe. Here\'s my original data:

pd.DataFrame([
        {\'col1\': 1, \'col2\': 11, \'col3\': [1, 2] },
        {\'col1\         


        

Answer 1

You can use a list comprehension together with zip.

>>> pd.DataFrame([row for row, count in zip(df[['col1', 'col2']].values, df['col3']) 
                  for _ in range(len(count))], columns=df.columns[:2])
   col1  col2
0     1    11
1     1    11
2     2    22
3     2    22
4     2    22
5     3    33
6     4    44
7     4    44
8     4    44
9     4    44

Answer 2

You can also use reindex and index.repeat

df = df.reindex(df.index.repeat(df.col3.apply(len)))

df = df.reset_index(drop=True).drop("col3", axis=1)
# To reset index and drop col3 

# Output:

   col1  col2
0   1     11
1   1     11
2   2     22
3   2     22
4   2     22
5   3     33
6   4     44
7   4     44
8   4     44
9   4     44