CodeQL documentation

Unreachable code

ID: py/unreachable-statement
Kind: problem
Severity: warning
Precision: very-high
   - maintainability
   - useless-code
   - external/cwe/cwe-561
Query suites:
   - python-security-and-quality.qls

Click to see the query in the CodeQL repository

Unreachable code makes the code more difficult to understand and may slow down loading of modules.


Deleting the unreachable code will make the code clearer and preserve the meaning of the code. However, it is possible that the original intention was that the code should execute and that it is unreachable signifies some other error.


In this example the assignment to remainder is never reached because there is a return statement on the previous line.

import math

def my_div(x, y):
    return math.floor(x / y)
    remainder = x - math.floor(x / y) * y