Conversion of non-standard time in Python

# -*- coding:utf-8 -*-
from datetime import datetime, timedelta
import re
import time


def tz_offset(tz):
    res = (re.search(r'(?P<F>[-+])(?P<H>\d{2}):?(?P<M>\d{2})', tz) or re.search('', '')).groupdict()
    offset = (1 if res.get('F', '+')=='+' else -1) * timedelta(
                        hours   = int(res.get('H', 0)),
                        minutes = int(res.get('M', 0)))
    return offset


def parse_date(data, fmt, tz):
    """
        Time matching module, which can be converted into fixed format
        Return time string 0000-00-00 00:00:00
        Matching structure | today ~ the day before yesterday, a few days ago, minutes and seconds ago | 2017-1-4 12:10 | 2017 / 1 / 4 12:10 | April 2, 2018 12:12
                        |April 2, 2018 | 2017-1-4 | 2017 / 1 / 4 | 1 / 4|
    """
    offset = tz_offset(tz)
    if fmt == 'auto':
        now = (datetime.utcnow() + timedelta(hours=8)).replace(microsecond=0) + offset
        now_1 = now - timedelta(days=1)
        now_2 = now - timedelta(days=2)

        #What day / just / today / yesterday / the day before yesterday
        x = data.strip()
        X = x.replace (U ',' 0 ')
        X = x.replace (U 'just [just]', now.strftime ('% Y -% m -% d% H:% m:% s'))
        X = x.replace (U 'today', now.strftime ('% Y -% m -% d'))
        X = x.replace (U 'yesterday', now_1. Strftime ('% Y -% m -% d'))
        X = x.replace (U 'day before yesterday', now_2.strftime ('% Y -% m -% d'))
        X = re.sub (R '[year]', '/', x)
        X = re.sub (R '[day]', ', x)
        x = re.sub(r'\s{2,}', r' ', x)

        #Before XX
        Res = (re. Search (R '(? P < s > \ D +) \ s * seconds ago', x)\
               Or re. Search (R '(? P < m > \ D +) \ s * minutes ago', x)\
               Or re. Search (R '(? P < H > \ D +) \ s * hours ago', x)\
               Or re. Search (R '(? P < d > \ D +) \ s * days ago', x)\
               or re.search('', '')).groupdict()
        if res:
            dt = now - timedelta(
                days=int(res.get('d', 0)),
                hours=int(res.get('H', 0)),
                minutes=int(res.get('M', 0)),
                seconds=int(res.get('S', 0))
            )
        #Not in the form of a few minutes ago
        else:
            # XX-XX-XX XX:XX:XX
            res = (re.search(r'(?P<Y>\d+)[/-](?P<m>\d+)[/-](?P<d>\d+)(\s+(?P<H>\d{1,2}):(?P<M>\d{2})(:(?P<S>\d{2}))?)?',
                             x) or re.search('', '')).groupdict()
            if res == dict():
                #When there is no year matching, the format is XX-XX XX: XX: XX month day hour: minute: second or October 10, 2017 hour: minute: second
                res = (re.search(
                    r'(?P<m>\d{1,2})[/-](?P<d>\d+)(\s+(?P<H>\d{2}):(?P<M>\d{2})(:(?P<S>\d{2}))?)?',
                    x) or re.search('', '')).groupdict()
            if res:
                Y = res.get('Y', now.year)
                Y = "20" + Y if len(str(Y)) == 2 else Y
                m = res.get('m', now.month)
                d = res.get('d', now.day)
                H = res.get('H', now.hour)
                M = res.get('M', now.minute)
                S = res.get('S', 0)
                dt = datetime(
                    year=int(Y) if Y != None and 1987 <= int(Y) <= now.year else now.year,
                    month=int(m) if m != None else now.month,
                    day=int(d) if d != None else now.day,
                    #If there are no hours, minutes and seconds, it is considered as 00:00:00
                    hour=int(H) if H != None else 0,
                    minute=int(M) if M != None else 0,
                    second=int(S) if S != None else 0
                )
            else:
                # 1970-01-01 00:00:00
                # dt = datetime.utcfromtimestamp(0)+offset
                return ""
        #The time may exceed the current time. If it exceeds the current time, subtract one year
        if int(time.mktime((dt - offset).timetuple())) > int(time.time()):
            #If the time exceeds the current time, subtract one year
            delta = timedelta(days=-365)
            real_time = (dt - offset) + delta
            real_time = real_time.strftime("%Y-%m-%d %H:%M:%S")
        else:
            real_time = (dt - offset).strftime("%Y-%m-%d %H:%M:%S")
        return real_time


if __name__ == '__main__':
    Print (parse_date ('2 seconds ago ',' auto ',' '))
    Print (parse_date ('2 minutes ago ',' auto ',' '))
    Print (parse_date ('2 hours ago ',' auto ',' '))
    Print (parse_date ('Yesterday 00:30 ','auto', ''))
    print(parse_date('07-20', 'auto', ''))