Class ExceptionTrap

Lib/importlib/metadata/_context.py:8–118

A context manager that will catch certain exceptions and provide an indication they occurred. >>> with ExceptionTrap() as trap: ... raise Exception() >>> bool(trap) True >>> with ExceptionTrap() as trap: ... pass >>> bool(trap) False >>> with E

# from jaraco.context 6.1
class ExceptionTrap:
    """
    A context manager that will catch certain exceptions and provide an
    indication they occurred.

    >>> with ExceptionTrap() as trap:
    ...     raise Exception()
    >>> bool(trap)
    True

    >>> with ExceptionTrap() as trap:
    ...     pass
    >>> bool(trap)
    False

    >>> with ExceptionTrap(ValueError) as trap:
    ...     raise ValueError("1 + 1 is not 3")
    >>> bool(trap)
    True
    >>> trap.value
    ValueError('1 + 1 is not 3')
    >>> trap.tb
    <traceback object at ...>

    >>> with ExceptionTrap(ValueError) as trap:
    ...     raise Exception()
    Traceback (most recent call last):
    ...
    Exception

    >>> bool(trap)
    False
    """

    exc_info = None, None, None

    def __init__(self, exceptions=(Exception,)):
        self.exceptions = exceptions

    def __enter__(self):
        return self

    @property
    def type(self):
        return self.exc_info[0]

    @property
    def value(self):
        return self.exc_info[1]

    @property
    def tb(self):
        return self.exc_info[2]

    def __exit__(self, *exc_info):
        type = exc_info[0]
        matches = type and issubclass(type, self.exceptions)
        if matches: