How to convert string value like "4w 2d.." to timedelta?-CodePudding

I have incoming string data in format like "4w 2d 5h" (weeks(w), days(d), hours(h), minutes(m)), some it can have different number of parameters (from 1 to 4, e.g "1w", "2w 5h", "3w 1d 5h 3m", etc). I need to convert it to timedelta (datetime) format. The only way I know it is to split it and then use statements depending on the letter. But probably there is more efficient way?

CodePudding user response：

If you're sure the strings are well formatted then you could try to use re:

import re
from datetime import timedelta

re_td = re.compile(r"(\d )(w|d|h|m)")
units = {"w": "weeks", "d": "days", "h": "hours", "m": "minutes"}

def to_timedelta(string):
    return timedelta(**{units[u]: int(val) for val, u in re_td.findall(string)})

The pattern (\d )(w|d|h|m) looks for numbers followed by one of the allowed letters, and due to the grouping a match in .findall packs them into a tuple. If there could be whitespace between the number and the letter then use (\d )\s*(w|d|h|m) instead.