Applying Pandas melt() on a dataframe with multiple variable columns

Question

I have a dataframe. Rows are unique persons and columns are various action types taken. I need the data restructured to show the individual events by row. Here is my current and

Answer 1

r = df.roles
c = df.roles.str.count(',') + 1
i = df.index
df.loc[i.repeat(c)].assign(roles=','.join(r).split(','))

  company  employer_id                roles
0       a            1             engineer
0       a            1       data_scientist
0       a            1            architect
1       b            2             engineer
1       b            2  front_end_developer