support email format validator

[aconrad]

Before:

>>> import validictory
>>> validictory.validate("foo", {"type":"string", "format":"email"})
>>> 

After:

>>> import validictory
>>> validictory.validate("foo", {"type":"string", "format":"email"})
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "validictory/__init__.py", line 31, in validate
    return v.validate(data, schema)
  File "validictory/validator.py", line 574, in validate
    self._validate(data, schema)
  File "validictory/validator.py", line 577, in _validate
    self.__validate("_data", {"_data": data}, schema)
  File "validictory/validator.py", line 608, in __validate
    newschema.get(schemaprop))
  File "validictory/validator.py", line 470, in validate_format
    format_validator(self, fieldname, value, format_option)
  File "validictory/validator.py", line 91, in validate_format_email
    "not an email" % locals(), fieldname, value)
validictory.validator.FieldValidationError: Value 'foo' of field '_data' is not an email
>>> 

[jamesturk]

this looks like a GPL'd regex, no?

[aconrad]

Yes, it looks like it. I'm no lawyer, would this not work with the validictory MIT-like licence?

[paultag]

@aconrad - it would, but the resulting combined work (The GPL calls this a Modified work, as defined in section 0) - section 5 (Conveying Modified Source Versions) subsection c dicatates: "You must license the entire work, as a whole, under this License to anyone who comes into possession of a copy. This License will therefore apply, along with any applicable section 7 additional terms, to the whole of the work, and all its parts, regardless of how they are packaged."

This would result in the entire library being distributed under the GPL, since it'd be conveyed as single work.

Basically, yes, but it'd mean the project would turn into a GPL licensed project, which might not be what @jamesturk would like -- it's easier if we find something matching the license of validictory

[aconrad]

Make sense, thanks @paultag. The plumbing is in place to validate emails, I'll come up with another validator, there are plenty out there (but this one seemed to be the most complete and accurate at the time).

[paultag]

NP; thanks for the hack, @aconrad !

[aconrad]

Replaced with one from http://www.regular-expressions.info/email.html but I couldn't find any information about licensing...

[ldave]

why isn't this merged yet?

[jamesturk]

due to licensing concerns & this http://davidcel.is/blog/2012/09/06/stop-validating-email-addresses-with-regex/

it's easy enough for people to add an email validator in their own code if that's what they want, I'd prefer not support this mostly-bad practice from within validictory