strftime formatting #150
Description
Thanks for all the hard work on this package!
I'd like to make a request, similar to #62 but maybe a bit simpler. I'd like to be able to specify how I would like a datetime to be parsed. For example:
from parse import parse
parse("my date:{my_date:%Y%M%d}", "my date:20200403").groups = {"my_date": datetime.datetime(2020, 4, 3)}You'd need to construct a regex expression from a date format:
dt_format_to_regex = {symbol: "[0-9]{2}" for symbol in "ymdIMSUW"}
dt_format_to_regex.update({"-" + symbol: "[0-9]{1,2}" for symbol in "ymdIMS"})
dt_format_to_regex.update(
{
"a": "[Sun|Mon|Tue|Wed|Thu|Fri|Sat]",
"A": "[Sunday|Monday|Tuesday|Wednesday|Thursday|Friday|Saturday]",
"Y": "[0-9]{4}",
"H": "[0-9]{1,2}",
"B": "[January|February|March|April|May|June|July|August|September|October|November|December]",
"b": "[Jan|Feb|Mar|Apr|May|Jun|Jul|Aug|Sep|Oct|Nov|Dec]",
"f": "[0-9]{6}",
"p": "[AM|PM]",
"z": "[+|-][0-9]{4}",
"j": "[0-9]{3}",
"-j": "[0-9]{1,3}",
}
)
def get_regex_for_datetime_format(format_):
regex = copy(format_)
for k, v in dt_format_to_regex.items():
regex = regex.replace(f"%{k}", v)
return regexand you'd need to parse the string into a datetime, which is actually quite easy because you can just rely on datetime.datetime.strptime:
self._type_conversions[group] = lambda x: datetime.strptime(x, format)I guess the remaining bit would be to determine if the formatting is of a datetime, but that doesn't seem that hard to me. As a first pass, you could just look for "%Y" in the format string. Technically datetime.datetime.strptime does allow you to parse datestrings that do not have a year, but that results are non-sensical, so it would be fine to not support them:
print(datetime.datetime.strptime("Sun", "%a"))
print(datetime.datetime.strptime("Mon", "%a"))datetime.datetime(1900, 1, 1, 0, 0)
datetime.datetime(1900, 1, 1, 0, 0)