Normalizing string to date in cerbrus

问题

i'm trying to normalize string as date so that in validation it can validate date data type.

from cerberus import Validator
from datetime import datetime

v = Validator()
v.schema = {'start_date': {'type': 'date','coerce':datetime.date}}
v.validate({'start_date': '2017-10-01'})
>>> False

but it still returns false. I have tried to use the integer and it works not sure why date conversion is not working.

v = Validator()
v.schema = {'amount': {'type': 'integer','coerce': int}}
v.validate({'amount': '2'})
>>> True

Any help would be appreciated.

回答1:

I am afraid that datetime.date alone won't convert a string to a date value. If you try that in the REPL this is what you get:

>>> datetime.date('2017-10-01')
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
TypeError: descriptor 'date' requires a 'datetime.datetime' object but received a 'str'

Try something like this instead:

from cerberus import Validator
from datetime import datetime

v = Validator()
to_date = lambda s: datetime.strptime(s, '%Y-%m-%d')
v.schema = {'start_date': {'type': 'datetime','coerce': to_date}}
v.validate({'start_date': '2017-10-01'})
>>> True

回答2:

Maybe this way is better to use:

def to_date(s):
    return datetime.strptime(s, '%Y-%m-%d')

来源：https://stackoverflow.com/questions/50133185/normalizing-string-to-date-in-cerbrus