| import re | |
| from typing import Dict | |
| from isoduration.constants import PERIOD_PREFIX, TIME_PREFIX, WEEK_PREFIX | |
| from isoduration.parser.exceptions import OutOfDesignators | |
| def is_period(ch: str) -> bool: | |
| return ch == PERIOD_PREFIX | |
| def is_time(ch: str) -> bool: | |
| return ch == TIME_PREFIX | |
| def is_week(ch: str) -> bool: | |
| return ch == WEEK_PREFIX | |
| def is_number(ch: str) -> bool: | |
| return bool(re.match(r"[+\-0-9.,eE]", ch)) | |
| def is_letter(ch: str) -> bool: | |
| return ch.isalpha() and ch.lower() != "e" | |
| def parse_designator(designators: Dict[str, str], target: str) -> str: | |
| while True: | |
| try: | |
| key, value = designators.popitem(last=False) # type: ignore | |
| except KeyError as exc: | |
| raise OutOfDesignators from exc | |
| if key == target: | |
| return value | |