Method _re_compile

xarray/core/accessor_str.py:243–281

(
        self,
        *,
        pat: str | bytes | Pattern | Any,
        flags: int = 0,
        case: bool | None = None,
    )

        )

    def _re_compile(
        self,
        *,
        pat: str | bytes | Pattern | Any,
        flags: int = 0,
        case: bool | None = None,
    ) -> Pattern | Any:
        is_compiled_re = isinstance(pat, re.Pattern)

        if is_compiled_re and flags != 0:
            raise ValueError("Flags cannot be set when pat is a compiled regex.")

        if is_compiled_re and case is not None:
            raise ValueError("Case cannot be set when pat is a compiled regex.")

        if is_compiled_re:
            # no-op, needed to tell mypy this isn't a string
            return re.compile(pat)

        if case is None:
            case = True

        # The case is handled by the re flags internally.
        # Add it to the flags if necessary.
        if not case:
            flags |= re.IGNORECASE

        if getattr(pat, "dtype", None) != np.object_:
            pat = self._stringify(pat)

        def func(x):
            return re.compile(x, flags=flags)

        if isinstance(pat, np.ndarray):
            # apply_ufunc doesn't work for numpy arrays with output object dtypes
            func_ = np.vectorize(func)
            return func_(pat)
        else:
            return _apply_str_ufunc(func=func, obj=pat, dtype=np.object_)

    def len(self) -> T_DataArray:
        """