Use of the return value of a procedure¶
ID: py/procedure-return-value-used Kind: problem Security severity: Severity: warning Precision: high Tags: - quality - maintainability - readability Query suites: - python-code-quality.qls - python-security-and-quality.qls Click to see the query in the CodeQL repository
All functions in Python return a value. If a function has no return statements or none of the return statements return a value then the function will return None. However, this value has no meaning and should be ignored.
Using the return value of such a ‘procedure’ is confusing to the reader as it suggests that the value is significant.
Recommendation¶
Do not use the return value of a procedure; replace x = proc() with proc() and replace any use of the value with None.
Example¶
In this example, the my_print function is a procedure as it returns no value of any meaning. Using the return value is misleading in subsequent code.
import sys def my_print(*args): print (args) def main(): err = my_print(sys.argv) if err: sys.exit(err) #FIXED VERSION def main(): my_print(sys.argv) #The rest of the code can be removed as None as always false References¶
Python Library Reference: None.