def _type_check(self, type_constraint, datum, is_input):
"""Typecheck a PTransform related datum according to a type constraint.
This function is used to optionally type-check either an input or an output
to a PTransform.
Args:
type_constraint: An instance of a typehints.TypeContraint, one of the
white-listed builtin Python types, or a custom user class.
datum: An instance of a Python object.
is_input: True if 'datum' is an input to a PTransform's DoFn. False
otherwise.
Raises:
TypeError: If 'datum' fails to type-check according to 'type_constraint'.
"""
datum_type = 'input' if is_input else 'output'
try:
check_constraint(type_constraint, datum)
except CompositeTypeHintError as e:
raise TypeCheckError, e.message, sys.exc_info()[2]
except SimpleTypeHintError:
error_msg = (
"According to type-hint expected %s should be of type %s. "
"Instead, received '%s', an instance of type %s." %
(datum_type, type_constraint, datum, type(datum)))
raise TypeCheckError, error_msg, sys.exc_info()[2]
def _check_instance_type(
type_constraint, instance, var_name=None, verbose=False):
"""A helper function to report type-hint constraint violations.
Args:
type_constraint: An instance of a 'TypeConstraint' or a built-in Python
type.
instance: The candidate object which will be checked by to satisfy
'type_constraint'.
var_name: If 'instance' is an argument, then the actual name for the
parameter in the original function definition.
Raises:
TypeCheckError: If 'instance' fails to meet the type-constraint of
'type_constraint'.
"""
hint_type = (
"argument: '%s'" % var_name if var_name is not None else 'return type')
try:
check_constraint(type_constraint, instance)
except SimpleTypeHintError:
if verbose:
verbose_instance = '%s, ' % instance
else:
verbose_instance = ''
raise TypeCheckError('Type-hint for %s violated. Expected an '
'instance of %s, instead found %san instance of %s.'
% (hint_type, type_constraint,
verbose_instance, type(instance)))
except CompositeTypeHintError as e:
raise TypeCheckError('Type-hint for %s violated: %s' % (hint_type, e))
def _type_check(self, type_constraint, datum, is_input):
"""Typecheck a PTransform related datum according to a type constraint.
This function is used to optionally type-check either an input or an output
to a PTransform.
Args:
type_constraint: An instance of a typehints.TypeContraint, one of the
white-listed builtin Python types, or a custom user class.
datum: An instance of a Python object.
is_input: True if 'datum' is an input to a PTransform's DoFn. False
otherwise.
Raises:
TypeError: If 'datum' fails to type-check according to 'type_constraint'.
"""
datum_type = 'input' if is_input else 'output'
try:
check_constraint(type_constraint, datum)
except CompositeTypeHintError as e:
raise TypeCheckError, e.message, sys.exc_info()[2]
except SimpleTypeHintError:
error_msg = ("According to type-hint expected %s should be of type %s. "
"Instead, received '%s', an instance of type %s."
% (datum_type, type_constraint, datum, type(datum)))
raise TypeCheckError, error_msg, sys.exc_info()[2]
def _check_instance_type(type_constraint,
instance,
var_name=None,
verbose=False):
"""A helper function to report type-hint constraint violations.
Args:
type_constraint: An instance of a 'TypeConstraint' or a built-in Python
type.
instance: The candidate object which will be checked by to satisfy
'type_constraint'.
var_name: If 'instance' is an argument, then the actual name for the
parameter in the original function definition.
Raises:
TypeCheckError: If 'instance' fails to meet the type-constraint of
'type_constraint'.
"""
hint_type = ("argument: '%s'" %
var_name if var_name is not None else 'return type')
try:
check_constraint(type_constraint, instance)
except SimpleTypeHintError:
if verbose:
verbose_instance = '%s, ' % instance
else:
verbose_instance = ''
raise TypeCheckError(
'Type-hint for %s violated. Expected an '
'instance of %s, instead found %san instance of %s.' %
(hint_type, type_constraint, verbose_instance, type(instance)))
except CompositeTypeHintError as e:
raise TypeCheckError('Type-hint for %s violated: %s' % (hint_type, e))
