import datetime from datetime import timedelta import re from itertools import repeat days_long = ['monday', 'tuesday', 'wednesday', 'thursday', 'friday', 'saturday', 'sunday'] days_short = ['mon', 'tue', 'wed', 'thu', 'fri', 'sat', 'sun'] days = days_long + days_short months_long = ['january', 'february', 'march', 'april', 'may', 'june', 'july', 'august', 'september', 'october', 'november', 'december'] months_short = ['jan', 'feb', 'march', 'april', 'may', 'june', 'july', 'aug', 'sept', 'oct', 'nov', 'dec'] months = months_long + months_short years = list(map(str, range(datetime.datetime.now().year - 50, datetime.datetime.now().year + 50))) postfixes = { 'h': 'hour', 'm': 'minute', 'd': 'day', } time_prefix = 'at' time_postfix = ['am', 'pm'] day_postfix = 'th' multipliers = { 'second': ('seconds', 1), 'minute': ('minutes', 1), 'hour': ('hours', 1), 'day': ('days', 1), 'week': ('days', 7), 'fortnight': ('days', 14), 'month': ('days', 30), 'year': ('days', 365), } direction = { 'ago': -1, 'last': -1, 'past': -1, } symbols = ['!', ',', '@', '#', '$', '%', '^', '&', '*', '?'] transformations = [dict(zip((x + 's' for x in multipliers.keys()), multipliers.keys()))] transformations.append(dict(zip(direction.keys(), (x + ' ' + '1' for x in direction.keys())))) transformations.append({ 'tomorrow': 'next day', 'yesterday': 'past 1 day' }) transformations.append({ 'next': '1', 'upcoming': '1', 'following': '1', 'a': '1', 'an': '1' }) keywords = list(multipliers.keys()) + months + months_short + years + days + days_short + list(direction.keys()) + [time_prefix] + time_postfix text = '12 jan 2019 at 12 will be amazing' def tokenize(string): sym_pattern = re.compile(r'([!,@#$%^&*?\'"])') string = sym_pattern.sub(lambda x: ' {} '.format(x.group()), string) for ts in transformations: pattern = re.compile(r'\b(' + '|'.join(ts.keys()) + r')\b') string = pattern.sub(lambda x: ts[x.group()], string) words = string.lower().split(' ') n = len(words) filtered = [] for (i, w) in enumerate(words): if w in keywords: filtered.append(w) elif w.isdigit() and ((i + 1 < n and words[i + 1] in keywords) or (i > 0 and words[i - 1] == time_prefix)): filtered.append(int(w)) elif w[0:-1].isdigit(): postfix = next((x for x in postfixes if w.endswith(x)), None) if postfix is not None: filtered.append(int(w[0:-1])) filtered.append(postfixes[postfix]) elif w[0:-2].isdigit() and w[-2:] in time_postfix and int(w[0:-2]) <= 12: filtered.append(int(w[0:-2])) filtered.append(w[-2:]) elif w[0:-2].isdigit() and w[-2:] == day_postfix: filtered.append(int(w[0:-2])) filtered.append(day_postfix) elif ':' in w: f, s = w[0:w.index(':')], w[w.index(':') + 1:] if f.isdigit() and s.isdigit() and int(f) < 24 and int(s) < 60: filtered.append((int(f), int(s))) return filtered def compute(tokens): base = datetime.datetime.now() value = timedelta(0) month = None weekday = None day = None year = None time = None cdir = 1 n = len(tokens) for (i, t) in enumerate(tokens): has_next = i + 1 < n if t in direction: cdir = direction[t] elif isinstance(t, int) and has_next and tokens[i + 1] in multipliers: key, v = multipliers[tokens[i + 1]] value += timedelta(**{ key: t * v }) elif isinstance(t, int) and has_next and (tokens[i + 1] in months or tokens[i + 1] == day_postfix): day = t elif isinstance(t, int) and has_next and tokens[i + 1] in time_postfix: if tokens[i + 1] == 'am': if t == 12: time = datetime.time(0) else: time = datetime.time(t) else: if t == 12: time = datetime.time(12) else: time = datetime.time(t + 12) elif t in months: month = months.index(t) % 12 elif t in years: year = t elif t in days: weekday = days.index(t) % 7 elif isinstance(t, tuple): f,s = t time = datetime.time(f, s) elif t == time_prefix and has_next and isinstance(tokens[i + 1], int) and tokens[i + 1] < 24: time = datetime.time(tokens[i + 1]) tokens[i + 1] = None try: if time is not None: base = base.replace(hour=time.hour, minute=time.minute) if month is not None: base = base.replace(month=month + 1) if weekday is not None: td = None if weekday > base.weekday(): td = timedelta(days=weekday - base.weekday()) else: td = timedelta(days=weekday - base.weekday() + 7) if cdir == -1: td = timedelta(days=7) - td base += cdir * td if year is not None: base = base.replace(year=int(year)) if day is not None: base = base.replace(day=day) except: pass return cdir * value + base def parse_date(string): return compute(tokenize(string))