Used when a bare raise is not used inside an except clause. This generates an error, since there are no active exceptions to be reraised. An exception to this rule is represented by a bare raise inside a finally clause, which might work, as long as an exception is raised inside the try block, but it is nevertheless a code smell that must not be relied upon.

Noncompliant Code:

def foo(x):
    if x <= 10:
        raise

Compliant Code:

def foo(x):
    if x <= 10:
        raise ValueError('x should be equal or grater than 10.')