import dataclasses
import inspect
from contextlib import contextmanager
from contextvars import ContextVar
from typing import Optional, Union
from .namespace import Namespace
from .type_checking import ArgumentParser
parent_parser: ContextVar['ArgumentParser'] = ContextVar('parent_parser')
parser_capture: ContextVar[bool] = ContextVar('parser_capture', default=False)
defaults_cache: ContextVar[Optional[Namespace]] = ContextVar('defaults_cache', default=None)
lenient_check: ContextVar[Union[bool, str]] = ContextVar('lenient_check', default=False)
load_value_mode: ContextVar[Optional[str]] = ContextVar('load_value_mode', default=None)
parser_context_vars = dict(
parent_parser=parent_parser,
parser_capture=parser_capture,
defaults_cache=defaults_cache,
lenient_check=lenient_check,
load_value_mode=load_value_mode,
)
@contextmanager
def parser_context(**kwargs):
context_var_tokens = []
for name, value in kwargs.items():
context_var = parser_context_vars[name]
token = context_var.set(value)
context_var_tokens.append((context_var, token))
try:
yield
finally:
for context_var, token in context_var_tokens:
context_var.reset(token)
def is_subclass(cls, class_or_tuple) -> bool:
"""Extension of issubclass that supports non-class arguments."""
try:
return inspect.isclass(cls) and issubclass(cls, class_or_tuple)
except TypeError:
return False
[docs]def is_final_class(cls) -> bool:
"""Checks whether a class is final, i.e. decorated with ``typing.final``."""
return getattr(cls, '__final__', False)
def is_dataclass_like(cls) -> bool:
if not inspect.isclass(cls):
return False
if is_final_class(cls):
return True
classes = [c for c in inspect.getmro(cls) if c != object]
all_dataclasses = all(dataclasses.is_dataclass(c) for c in classes)
from .optionals import attrs_support, pydantic_support
if not all_dataclasses and pydantic_support:
import pydantic.utils
classes = [c for c in classes if c != pydantic.utils.Representation]
all_dataclasses = all(is_subclass(c, pydantic.BaseModel) for c in classes)
if not all_dataclasses and attrs_support:
import attrs
if attrs.has(cls):
return True
return all_dataclasses