Manipulating List

[perfringo]

Just for oneliner fun:

>>> names = 'Cohn, Mildred; Dolciani, Mary P.; Rees, Mina; Teitelbaum, Ruth; Yalow, Rosalyn'
>>> print(*[f'{item[1][0]}. {item[0]}' for item in [name.split(', ') for name in names.split('; ')]], sep='\n')
M. Cohn
M. Dolciani
M. Rees
R. Teitelbaum
R. Yalow

EDIT: to get expected output ('You entered:' followed by empty line):

>>> print('You entered:\n', *[f'{item[1][0]}. {item[0]}' for item in [name.split(', ') for name in names.split('; ')]], sep='\n')
You entered:

M. Cohn
M. Dolciani
M. Rees
R. Teitelbaum
R. Yalow