Function inspect_formatargspec

lib/sqlalchemy/util/compat.py:187–256

Copy formatargspec from python 3.7 standard library. Python 3 has deprecated formatargspec and requested that Signature be used instead, however this requires a full reimplementation of formatargspec() in terms of creating Parameter objects and such. Instead of introducing all the o

(
    args: List[str],
    varargs: Optional[str] = None,
    varkw: Optional[str] = None,
    defaults: Optional[Sequence[Any]] = None,
    kwonlyargs: Optional[Sequence[str]] = (),
    kwonlydefaults: Optional[Mapping[str, Any]] = {},
    annotations: Mapping[str, Any] = {},
    formatarg: Callable[[str], str] = str,
    formatvarargs: Callable[[str], str] = lambda name: "*" + name,
    formatvarkw: Callable[[str], str] = lambda name: "**" + name,
    formatvalue: Callable[[Any], str] = lambda value: "=" + repr(value),
    formatreturns: Callable[[Any], str] = lambda text: " -> " + str(text),
    formatannotation: Callable[[Any], str] = _formatannotation,
)

def inspect_formatargspec(
    args: List[str],
    varargs: Optional[str] = None,
    varkw: Optional[str] = None,
    defaults: Optional[Sequence[Any]] = None,
    kwonlyargs: Optional[Sequence[str]] = (),
    kwonlydefaults: Optional[Mapping[str, Any]] = {},
    annotations: Mapping[str, Any] = {},
    formatarg: Callable[[str], str] = str,
    formatvarargs: Callable[[str], str] = lambda name: "*" + name,
    formatvarkw: Callable[[str], str] = lambda name: "**" + name,
    formatvalue: Callable[[Any], str] = lambda value: "=" + repr(value),
    formatreturns: Callable[[Any], str] = lambda text: " -> " + str(text),
    formatannotation: Callable[[Any], str] = _formatannotation,
) -> str:
    """Copy formatargspec from python 3.7 standard library.

    Python 3 has deprecated formatargspec and requested that Signature
    be used instead, however this requires a full reimplementation
    of formatargspec() in terms of creating Parameter objects and such.
    Instead of introducing all the object-creation overhead and having
    to reinvent from scratch, just copy their compatibility routine.

    Ultimately we would need to rewrite our "decorator" routine completely
    which is not really worth it right now, until all Python 2.x support
    is dropped.

    """

    kwonlydefaults = kwonlydefaults or {}
    annotations = annotations or {}

    def formatargandannotation(arg):
        result = formatarg(arg)
        if arg in annotations:
            result += ": " + formatannotation(annotations[arg])
        return result

    specs = []
    if defaults:
        firstdefault = len(args) - len(defaults)
    else:
        firstdefault = -1

    for i, arg in enumerate(args):
        spec = formatargandannotation(arg)
        if defaults and i >= firstdefault:
            spec = spec + formatvalue(defaults[i - firstdefault])
        specs.append(spec)

    if varargs is not None:
        specs.append(formatvarargs(formatargandannotation(varargs)))
    else:
        if kwonlyargs:
            specs.append("*")

    if kwonlyargs:
        for kwonlyarg in kwonlyargs: