inspect.py 2.3 KB

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  1. import functools
  2. import inspect
  3. @functools.lru_cache(maxsize=512)
  4. def _get_func_parameters(func, remove_first):
  5. parameters = tuple(inspect.signature(func).parameters.values())
  6. if remove_first:
  7. parameters = parameters[1:]
  8. return parameters
  9. def _get_callable_parameters(meth_or_func):
  10. is_method = inspect.ismethod(meth_or_func)
  11. func = meth_or_func.__func__ if is_method else meth_or_func
  12. return _get_func_parameters(func, remove_first=is_method)
  13. ARG_KINDS = frozenset(
  14. {
  15. inspect.Parameter.POSITIONAL_ONLY,
  16. inspect.Parameter.KEYWORD_ONLY,
  17. inspect.Parameter.POSITIONAL_OR_KEYWORD,
  18. }
  19. )
  20. def get_func_args(func):
  21. params = _get_callable_parameters(func)
  22. return [param.name for param in params if param.kind in ARG_KINDS]
  23. def get_func_full_args(func):
  24. """
  25. Return a list of (argument name, default value) tuples. If the argument
  26. does not have a default value, omit it in the tuple. Arguments such as
  27. *args and **kwargs are also included.
  28. """
  29. params = _get_callable_parameters(func)
  30. args = []
  31. for param in params:
  32. name = param.name
  33. # Ignore 'self'
  34. if name == "self":
  35. continue
  36. if param.kind == inspect.Parameter.VAR_POSITIONAL:
  37. name = "*" + name
  38. elif param.kind == inspect.Parameter.VAR_KEYWORD:
  39. name = "**" + name
  40. if param.default != inspect.Parameter.empty:
  41. args.append((name, param.default))
  42. else:
  43. args.append((name,))
  44. return args
  45. def func_accepts_kwargs(func):
  46. """Return True if function 'func' accepts keyword arguments **kwargs."""
  47. return any(p for p in _get_callable_parameters(func) if p.kind == p.VAR_KEYWORD)
  48. def func_accepts_var_args(func):
  49. """
  50. Return True if function 'func' accepts positional arguments *args.
  51. """
  52. return any(p for p in _get_callable_parameters(func) if p.kind == p.VAR_POSITIONAL)
  53. def method_has_no_args(meth):
  54. """Return True if a method only accepts 'self'."""
  55. count = len([p for p in _get_callable_parameters(meth) if p.kind in ARG_KINDS])
  56. return count == 0 if inspect.ismethod(meth) else count == 1
  57. def func_supports_parameter(func, name):
  58. return any(param.name == name for param in _get_callable_parameters(func))