1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
|
# Python's datetime strftime doesn't handle dates before 1900.
# These classes override date and datetime to support the formatting of a date
# through its full "proleptic Gregorian" date range.
#
# Based on code submitted to comp.lang.python by Andrew Dalke
#
# >>> datetime_safe.date(1850, 8, 2).strftime("%Y/%m/%d was a %A")
# '1850/08/02 was a Friday'
import re
import time as ttime
from datetime import (
date as real_date, datetime as real_datetime, time as real_time,
)
class date(real_date):
def strftime(self, fmt):
return strftime(self, fmt)
class datetime(real_datetime):
def strftime(self, fmt):
return strftime(self, fmt)
@classmethod
def combine(cls, date, time):
return cls(date.year, date.month, date.day,
time.hour, time.minute, time.second,
time.microsecond, time.tzinfo)
def date(self):
return date(self.year, self.month, self.day)
class time(real_time):
pass
def new_date(d):
"Generate a safe date from a datetime.date object."
return date(d.year, d.month, d.day)
def new_datetime(d):
"""
Generate a safe datetime from a datetime.date or datetime.datetime object.
"""
kw = [d.year, d.month, d.day]
if isinstance(d, real_datetime):
kw.extend([d.hour, d.minute, d.second, d.microsecond, d.tzinfo])
return datetime(*kw)
# This library does not support strftime's "%s" or "%y" format strings.
# Allowed if there's an even number of "%"s because they are escaped.
_illegal_formatting = re.compile(r"((^|[^%])(%%)*%[sy])")
def _findall(text, substr):
# Also finds overlaps
sites = []
i = 0
while 1:
j = text.find(substr, i)
if j == -1:
break
sites.append(j)
i = j + 1
return sites
def strftime(dt, fmt):
if dt.year >= 1900:
return super(type(dt), dt).strftime(fmt)
illegal_formatting = _illegal_formatting.search(fmt)
if illegal_formatting:
raise TypeError("strftime of dates before 1900 does not handle" + illegal_formatting.group(0))
year = dt.year
# For every non-leap year century, advance by
# 6 years to get into the 28-year repeat cycle
delta = 2000 - year
off = 6 * (delta // 100 + delta // 400)
year = year + off
# Move to around the year 2000
year = year + ((2000 - year) // 28) * 28
timetuple = dt.timetuple()
s1 = ttime.strftime(fmt, (year,) + timetuple[1:])
sites1 = _findall(s1, str(year))
s2 = ttime.strftime(fmt, (year + 28,) + timetuple[1:])
sites2 = _findall(s2, str(year + 28))
sites = []
for site in sites1:
if site in sites2:
sites.append(site)
s = s1
syear = "%04d" % (dt.year,)
for site in sites:
s = s[:site] + syear + s[site + 4:]
return s
|