Method __repr__

src/_pytest/python_api.py:390–417

Return a string communicating both the expected value and the tolerance for the comparison being made. For example, ``1.0 ± 1e-6``, ``(3+4j) ± 5e-6 ∠ ±180°``.

(self)

    DEFAULT_RELATIVE_TOLERANCE: Union[float, Decimal] = 1e-6

    def __repr__(self) -> str:
        """Return a string communicating both the expected value and the
        tolerance for the comparison being made.

        For example, ``1.0 ± 1e-6``, ``(3+4j) ± 5e-6 ∠ ±180°``.
        """
        # Don't show a tolerance for values that aren't compared using
        # tolerances, i.e. non-numerics and infinities. Need to call abs to
        # handle complex numbers, e.g. (inf + 1j).
        if (not isinstance(self.expected, (Complex, Decimal))) or math.isinf(
            abs(self.expected)  # type: ignore[arg-type]
        ):
            return str(self.expected)

        # If a sensible tolerance can't be calculated, self.tolerance will
        # raise a ValueError.  In this case, display '???'.
        try:
            vetted_tolerance = f"{self.tolerance:.1e}"
            if (
                isinstance(self.expected, Complex)
                and self.expected.imag
                and not math.isinf(self.tolerance)
            ):
                vetted_tolerance += " ∠ ±180°"
        except ValueError:
            vetted_tolerance = "???"

        return f"{self.expected} ± {vetted_tolerance}"

    def __eq__(self, actual) -> bool:
        """Return whether the given value is equal to the expected value