python strptime format with optional bits

Question

Right now I have:

timestamp = datetime.strptime(date_string, \'%Y-%m-%d %H:%M:%S.%f\')

This works great unless I\'m converting a string tha

Answer 1

using one regular expression and some list expressions

time_str = "12:34.567"
# time format is [HH:]MM:SS[.FFF]
sum([a*b for a,b in zip(map(lambda x: int(x) if x else 0, re.match(r"(?:(\d{2}):)?(\d{2}):(\d{2})(?:\.(\d{3}))?", time_str).groups()), [3600, 60, 1, 1/1000])])
# result = 754.567