Is there a way to have Cerberus validate that two fields have the same amount of elements?
For instance, this document would validate:
{'a': [1, 2, 3], b: [4, 5, 6]}
And this won't:
{'a': [1, 2, 3], 'b': [7, 8]}
So far I have come up with this schema:
{'a': {'required':False, 'type'= 'list', 'dependencies':'b'},
'b': {'required':False, 'type'= 'list', 'dependencies':'a'}}
But there's no rule to test the equal length of two fields.
With a custom rule it is pretty straight-forward:
>>> from cerberus import Validator
>>> class MyValidator(Validator):
def _validate_match_length(self, other, field, value):
if other not in self.document:
return False
if len(value) != len(self.document[other]):
self._error(field,
"Length doesn't match field %s's length." % other)
>>> schema = {'a': {'type': 'list', 'required': True},
'b': {'type': 'list', 'required': True, 'match_length': 'a'}}
>>> validator = MyValidator(schema)
>>> document = {'a': [1, 2, 3], 'b': [4, 5, 6]}
>>> validator(document)
True
>>> document = {'a': [1, 2, 3], 'b': [7, 8]}
>>> validator(document)
False
来源:https://stackoverflow.com/questions/45721326/validating-that-two-params-have-same-amount-elements-using-cerberus