The only two possible types for an ``++except++``'s expression are a class deriving from ``++BaseException++``, or a tuple composed of such classes (or an old style class if you are using python 2, but this has been removed in python 3).


This rule raises an issue when the expression used in an ``++except++`` block is a boolean expression of exceptions. The result of such expression is a single exception class, which is valid but not what the developer intended.

== Noncompliant Code Example

----
try:
    raise TypeError()
except ValueError or TypeError:  # Noncompliant
    print("Catching only ValueError")
except ValueError and TypeError:  # Noncompliant
    print("catching only TypeError")
except (ValueError or TypeError) as exception:  # Noncompliant
    print("Catching only ValueError")

foo = ValueError or TypeError  # foo == ValueError
foo = ValueError and TypeError  # foo == TypeError
----

== Compliant Solution

----
try:
    raise TypeError()
except (ValueError, TypeError) as exception:
    print("Catching all exceptions")
----

== See

* Python documentation - https://docs.python.org/3/reference/compound_stmts.html#except[the ``++try++`` statement]