Function register_option

pandas/_config/config.py:521–593

Register an option in the package-wide pandas config object Parameters ---------- key : str Fully-qualified key, e.g. "x.y.option - z". defval : object Default value of the option. doc : str Description of the option. validator : Callable, option

(
    key: str,
    defval: object,
    doc: str = "",
    validator: Callable[[object], Any] | None = None,
    cb: Callable[[str], Any] | None = None,
)

def register_option(
    key: str,
    defval: object,
    doc: str = "",
    validator: Callable[[object], Any] | None = None,
    cb: Callable[[str], Any] | None = None,
) -> None:
    """
    Register an option in the package-wide pandas config object

    Parameters
    ----------
    key : str
        Fully-qualified key, e.g. "x.y.option - z".
    defval : object
        Default value of the option.
    doc : str
        Description of the option.
    validator : Callable, optional
        Function of a single argument, should raise `ValueError` if
        called with a value which is not a legal value for the option.
    cb
        a function of a single argument "key", which is called
        immediately after an option value is set/reset. key is
        the full name of the option.

    Raises
    ------
    ValueError if `validator` is specified and `defval` is not a valid value.

    """
    import keyword
    import tokenize

    key = key.lower()

    if key in _registered_options:
        raise OptionError(f"Option '{key}' has already been registered")
    if key in _reserved_keys:
        raise OptionError(f"Option '{key}' is a reserved key")

    # the default value should be legal
    if validator:
        validator(defval)

    # walk the nested dict, creating dicts as needed along the path
    path = key.split(".")

    for k in path:
        if not re.match("^" + tokenize.Name + "$", k):
            raise ValueError(f"{k} is not a valid identifier")
        if keyword.iskeyword(k):
            raise ValueError(f"{k} is a python keyword")

    cursor = _global_config
    msg = "Path prefix to option '{option}' is already an option"

    for i, p in enumerate(path[:-1]):