def generate_signature_schema(func,
update_keys=None,
exclude_keys=frozenset()):
"""Generate a dictionary to test function signatures with Cerberus' Schema.
Parameters
----------
func : function
The function used to build the schema.
update_keys : dict
Keys in here have priority over automatic generation. It can be
used to make an argument mandatory, or to use a specific validator.
exclude_keys : list-like
Keys in here are ignored and not included in the schema.
Returns
-------
func_schema : dict
The dictionary to be used as Cerberus Validator schema. Contains all keyword
variables in the function signature as optional argument with
the default type as validator. Unit bearing strings are converted.
Argument with default None are always accepted. Camel case
parameters in the function are converted to underscore style.
Examples
--------
>>> from cerberus import Validator
>>> def f(a, b, camelCase=True, none=None, quantity=3.0*unit.angstroms):
... pass
>>> f_dict = generate_signature_schema(f, exclude_keys=['quantity'])
>>> print(isinstance(f_dict, dict))
True
>>> f_validator = Validator(generate_signature_schema(f))
>>> f_validator.validated({'quantity': '1.0*nanometer'})
{'quantity': Quantity(value=1.0, unit=nanometer)}
"""
if update_keys is None:
update_keys = {}
func_schema = {}
arg_spec = inspect.getfullargspec(unwrap_py2(func))
args = arg_spec.args
defaults = arg_spec.defaults
# Check keys that must be excluded from first pass
exclude_keys = set(exclude_keys)
exclude_keys.update(update_keys)
# Transform camelCase to underscore
args = [utils.camelcase_to_underscore(arg) for arg in args]
# Build schema
optional_validator = {
'required': False
} # Keys are always optional for this type
for arg, default_value in zip(args[-len(defaults):], defaults):
if arg not in exclude_keys: # User defined keys are added later
if default_value is None: # None defaults are always accepted, and considered nullable
validator = {'nullable': True}
elif isinstance(default_value,
unit.Quantity): # Convert unit strings
validator = {'coerce': to_unit_coercer(default_value.unit)}
else:
validator = type_to_cerberus_map(type(default_value))
# Add the argument to the existing schema as a keyword
# To the new keyword, add the optional flag and the "validator" flag
# of either 'validator' or 'type' depending on how it was processed
func_schema = {
**func_schema,
**{
arg: {
**optional_validator,
**validator
}
}
}
# Add special user keys
func_schema.update(update_keys)
return func_schema
def generate_signature_schema(func, update_keys=None, exclude_keys=frozenset()):
"""Generate a dictionary to test function signatures with Cerberus' Schema.
Parameters
----------
func : function
The function used to build the schema.
update_keys : dict
Keys in here have priority over automatic generation. It can be
used to make an argument mandatory, or to use a specific validator.
exclude_keys : list-like
Keys in here are ignored and not included in the schema.
Returns
-------
func_schema : dict
The dictionary to be used as Cerberus Validator schema. Contains all keyword
variables in the function signature as optional argument with
the default type as validator. Unit bearing strings are converted.
Argument with default None are always accepted. Camel case
parameters in the function are converted to underscore style.
Examples
--------
>>> from cerberus import Validator
>>> def f(a, b, camelCase=True, none=None, quantity=3.0*unit.angstroms):
... pass
>>> f_dict = generate_signature_schema(f, exclude_keys=['quantity'])
>>> print(isinstance(f_dict, dict))
True
>>> f_validator = Validator(generate_signature_schema(f))
>>> f_validator.validated({'quantity': '1.0*nanometer'})
{'quantity': Quantity(value=1.0, unit=nanometer)}
"""
if update_keys is None:
update_keys = {}
func_schema = {}
arg_spec = inspect.getfullargspec(unwrap_py2(func))
args = arg_spec.args
defaults = arg_spec.defaults
# Check keys that must be excluded from first pass
exclude_keys = set(exclude_keys)
exclude_keys.update(update_keys)
# Transform camelCase to underscore
args = [utils.camelcase_to_underscore(arg) for arg in args]
# Build schema
optional_validator = {'required': False} # Keys are always optional for this type
for arg, default_value in zip(args[-len(defaults):], defaults):
if arg not in exclude_keys: # User defined keys are added later
if default_value is None: # None defaults are always accepted, and considered nullable
validator = {'nullable': True}
elif isinstance(default_value, unit.Quantity): # Convert unit strings
validator = {'coerce': to_unit_coercer(default_value.unit)}
else:
validator = type_to_cerberus_map(type(default_value))
# Add the argument to the existing schema as a keyword
# To the new keyword, add the optional flag and the "validator" flag
# of either 'validator' or 'type' depending on how it was processed
func_schema = {**func_schema, **{arg: {**optional_validator, **validator}}}
# Add special user keys
func_schema.update(update_keys)
return func_schema