Non-exception in ‘except’ clause¶

ID: py/useless-except
Kind: problem
Security severity: 
Severity: error
Precision: very-high
Tags:
   - quality
   - reliability
   - error-handling
Query suites:
   - python-code-quality.qls
   - python-security-and-quality.qls

Click to see the query in the CodeQL repository

If the class specified in an except handler (within a try statement) is not a legal exception class, then it will never match a raised exception and never be executed

Legal exception classes are:

• Any old-style classes (Python 2 only)

• Any subclass of the builtin class BaseException However, it recommended that you only use subclasses of the builtin class Exception (which is itself a subclass of BaseException).

def handle_int():
    try:
        raise_int()
    #This will not cause an exception, but it will be ignored
    except int:
        print("This will never be printed")