grammer.py

import re

strings = """every day at 11:30
every 2nd week tuesday at 11:30
every 5 mins
"""

grammer = {
  "G": "every <DAY_CTX> | <WEEK_CTX> | <MIN_CTX>",
  "WEEK_CTX": "<WEEK> week <DAY_CTX>",
  "DAY_CTX": "<DAY> at <TIME>",
  "MIN_CTX": "<MIN> mins",
  "WEEK": "(?P<day_num>\d+)\w{2}",
  "DAY": "(?P<day>\w+)",
  "TIME": "(?P<hour>\d+):(?P<min>\d+)",
  "MIN": "(?P<min>\d+)"
}

_tag = r"<.*>"

def construct_grammer(gram_dict, key="G"):
  G = grammer.get(key)
  tags = re.find_all(_tag)
  for tag for tags:
    _constructed =