Created
March 8, 2012 12:42
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Python datetime.strftime < 1900 workaround
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| import datetime | |
| import re | |
| import warnings | |
| def strftime(dt, fmt): | |
| if dt.year < 1900: | |
| # create a copy of this datetime, just in case, then set the year to | |
| # something acceptable, then replace that year in the resulting string | |
| tmp_dt = datetime.datetime(datetime.MAXYEAR, dt.month, dt.day, | |
| dt.hour, dt.minute, | |
| dt.second, dt.microsecond, | |
| dt.tzinfo) | |
| if re.search('(?<!%)((?:%%)*)(%y)', fmt): | |
| warnings.warn("Using %y time format with year prior to 1900 " | |
| "could produce unusual results!") | |
| tmp_fmt = fmt | |
| tmp_fmt = re.sub('(?<!%)((?:%%)*)(%y)', '\\1\x11\x11', tmp_fmt, re.U) | |
| tmp_fmt = re.sub('(?<!%)((?:%%)*)(%Y)', '\\1\x12\x12\x12\x12', tmp_fmt, re.U) | |
| tmp_fmt = tmp_fmt.replace(str(datetime.MAXYEAR), '\x13\x13\x13\x13') | |
| tmp_fmt = tmp_fmt.replace(str(datetime.MAXYEAR)[-2:], '\x14\x14') | |
| result = tmp_dt.strftime(tmp_fmt) | |
| if '%c' in fmt: | |
| # local datetime format - uses full year but hard for us to guess | |
| # where. | |
| result = result.replace(str(datetime.MAXYEAR), str(dt.year)) | |
| result = result.replace('\x11\x11', str(dt.year)[-2:]) | |
| result = result.replace('\x12\x12\x12\x12', str(dt.year)) | |
| result = result.replace('\x13\x13\x13\x13', str(datetime.MAXYEAR)) | |
| result = result.replace('\x14\x14', str(datetime.MAXYEAR)[-2:]) | |
| return result | |
| else: | |
| return dt.strftime(fmt) |
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Thanks for sharing some code ... though in this case I'm not sure it's correct. What cases did you test? e.g. for "%A" I get
1800-12-31 00:00:00 Friday
1801-01-01 00:00:00 Friday
... which shouldn't both be true. :-)
There's some useful test code on this version: http://code.activestate.com/recipes/306860-proleptic-gregorian-dates-and-strftime-before-1900/ ... let me know if you'd like my updated test script.