import inspect
[docs]class Invalid:
"""Marker object for not serializable-object"""
[docs]def get_default_kwargs(func):
"""Get the default values of the input function.
Examples:
>>> def func(a, b=3): pass
>>> get_default_kwargs(func)
{'b': 3}
"""
def yaml_serializable(value):
# isinstance(x, tuple) includes namedtuple, so type is used here
if type(value) is tuple:
return yaml_serializable(list(value))
elif isinstance(value, set):
return yaml_serializable(list(value))
elif isinstance(value, dict):
if not all(isinstance(k, str) for k in value):
return Invalid
retval = {}
for k, v in value.items():
v2 = yaml_serializable(v)
# Register only valid object
if v2 not in (Invalid, inspect.Parameter.empty):
retval[k] = v2
return retval
elif isinstance(value, list):
retval = []
for v in value:
v2 = yaml_serializable(v)
# If any elements in the list are invalid,
# the list also becomes invalid
if v2 is Invalid:
return Invalid
else:
retval.append(v2)
return retval
elif value in (inspect.Parameter.empty, None):
return value
elif isinstance(value, (float, int, complex, bool, str, bytes)):
return value
else:
return Invalid
# params: An ordered mapping of inspect.Parameter
params = inspect.signature(func).parameters
data = {p.name: p.default for p in params.values()}
# Remove not yaml-serializable object
data = yaml_serializable(data)
return data