for python3:

is_pm = s.endswith('PM') time_part = s[:-2] hours = int(time_part[:2])

if is_pm:
    if hours != 12:
        hours += 12
else: 
    if hours == 12:
        hours = 0   

military_hours = f"{hours:02d}"
result = military_hours + time_part[2:]
return result