Creating multiple feature-columns using apply (or something else) on pandas column

Question

I have a dataframe:

df = pd.DataFrame({'col1': [69, 77, 88],
                   'col2': ['barfoo', 'foo', 'bar']})
print(df)

   col1    col2
0    69  barfoo
1    77     foo
2    88     bar 

Also I have function that returns two values based on string:

def get_first_n_second(string):
    '''
    Function returns two values for two columns
    '''
    value1 = string[0]
    value2 = string[1]
    return value1, value2

And I want to create two new columns based on col2 (it doesn`t work):

df[['first', 'second']] = df['col2'].apply(get_first_n_second)

Desired output:

   col1    col2   first   second
0    69  barfoo       b        a
1    77     foo       f        o
2    88     bar       b        a

Answer 1

There are 2 changes - return Series from function:

def get_first_n_second(string):
    '''
    Function returns two values for two columns
    '''
    value1 = string[0]
    value2 = string[1]
    return pd.Series([value1, value2])


df[['first', 'second']] = df['col2'].apply(get_first_n_second)
print (df)
   col1    col2 first second
0    69  barfoo     b      a
1    77     foo     f      o
2    88     bar     b      a