python dataframe how to pad to cerain number of rows

Question

I have multiple dataframe with number of rows that varies between 8,9,10. I want to take the dataframe with len 8,9 and add them rows of zeros - to make them with 10 rows also.

What is the best way to do so?

Answer 1

Use DataFrame.reindex in list comprehension:

dfs = [df1, df2, df3]
dfs = [x.reindex(range(10), fill_value=0) for x in dfs]

If need reindex by maximum index values create maximum length dynamically:

m = len(max(dfs, key=len))
dfs = [x.reindex(range(m), fill_value=0) for x in dfs]