def strftime(dt, fmt):
if dt.year >= 1900:
return super(type(dt), dt).strftime(fmt)
else:
illegal_formatting = _illegal_formatting.search(fmt)
if illegal_formatting is None:
year = dt.year
# For every non-leap year century, advance by 6 years to get into
# the 28-year repeat cycle
delta = 2000 - year
year += 6 * (delta // 100 + delta // 400)
year += ((2000 - year) // 28) * 28 # Move to around the year 2000
no_year_tuple = dt.timetuple()[1:]
sites = _year_find_all(fmt, year, no_year_tuple)
sites &= _year_find_all(fmt, year + 28, no_year_tuple)
res = _time_strftime(fmt, (year,) + no_year_tuple)
syear = "%04d" % dt.year
for site in sites:
res = res[:site] + syear + res[site + 4:]
return res
else:
msg = ('strftime of dates before 1900 does not handle'
' %s') % illegal_formatting.group(0)
raise TypeError(msg)
def _year_find_all(fmt, year, no_year_tuple):
text = _time_strftime(fmt, (year,) + no_year_tuple)
regex = _regex_compile(str(year))
return {match.start() for match in regex.finditer(text)}
