[NEW QUERY] Python bare except clause detection

[Copilot]

📝 Query Information

• Language: Python
• Query ID: py/bare-except
• Category: maintainability, code-quality
• Severity: warning
• CWE/CVE (if applicable): CWE-396

🎯 Description

What This Query Detects

Bare except: clauses catch all exceptions including SystemExit and KeyboardInterrupt, obscuring bugs and breaking signal handling.

Example Vulnerable Code

def parse_int(s: str) -> int:
    try:
        return int(s)
    except:  # Catches KeyboardInterrupt, SystemExit, etc.
        return 0

Example Safe Code

def parse_int(s: str) -> int:
    try:
        return int(s)
    except ValueError:  # Catches only expected error
        return 0

🧪 Testing

• Positive test cases included
• Negative test cases included
• Edge cases covered
• All tests pass

📋 Checklist

• Query compiles without errors
• Documentation complete (.md and .qhelp)
• Metadata properly set (@name, @id, @kind, etc.)
• Tests validate query behavior
• No false positives in test cases

🔗 References

• PEP 8 Programming Recommendations
• Python Exception Handling
• CWE-396: Declaration of Catch for Generic Exception

---

Note: This query was developed using Test-Driven Development methodology.

Original prompt

---

This section details on the original issue you should resolve

<issue_title>[Query Create]:</issue_title>
<issue_description>### Target Language

python

Query Name (Optional)

Bare Except

Query Type

Code Quality

Query Description

Bare except: (overly broad exception handling)

Why it’s a quality problem
Catching everything (including KeyboardInterrupt, SystemExit, etc.) can:

hide real bugs,
make failures harder to debug,
lead to incorrect behavior by swallowing critical exceptions.

Expected Severity

Medium

Code Examples

//should be detected
def parse_int(s: str) -> int:
try:
return int(s)
except: # <- too broad
return 0

//should NOT be detected
def parse_int(s: str) -> int:
try:
return int(s)
except ValueError:
return 0

CWE/CVE Reference (Optional)

No response

References (Optional)

No response

Code of Conduct

• I agree to follow this project's Code of Conduct</issue_description>

Comments on the Issue (you are @copilot in this section)

• Fixes [Query Create]: #1

---

✨ Let Copilot coding agent set things up for you — coding agent works faster and does higher quality work when set up for your repo.