lukemilby / validator.py

A library for validating that dictionary values meet certain sets of parameters. Much like form validators, but for dicts.

validator.py

A library for validating that dictionary values meet certain sets of parameters. Much like form validators, but for dicts.

Documentation

This README has some basic usage information, but more detailed documentation may be found at ReadTheDocs.

Usage Example

First, install it from PyPI.

pip install validator.py

from validator import Required, Not, Truthy, Blank, Range, Equals, In, validate

# let's say that my dictionary needs to meet the following rules...
rules = {
    "foo": [Required, Equals(123)],
    "bar": [Required, Truthy()],
    "baz": [In(["spam", "eggs", "bacon"])],
    "qux": [Not(Range(1, 100))] # by default, Range is inclusive
}

# then this following dict would pass:
passes = {
    "foo": 123,
    "bar": True, # or a non-empty string, or a non-zero int, etc...
    "baz": "spam",
    "qux": 101
}
print validate(rules, passes)
# (True, {})

# but this one would fail
fails = {
    "foo": 321,
    "bar": False, # or 0, or [], or an empty string, etc...
    "baz": "barf",
    "qux": 99
}
print validate(rules, fails)
# (False,
#  {
#  'foo': ["must be equal to '123'"],
#  'bar': ['must be True-equivalent value'],
#  'baz': ["must be one of ['spam', 'eggs', 'bacon']"],
#  'qux': ['must not fall between 1 and 100']
#  })