python.bare_except

Correctness Medium

Detects except: without an exception type, which catches all exceptions including KeyboardInterrupt and SystemExit.

Why It Matters

Bare except: catches everything, not just the errors you intended:

• KeyboardInterrupt — Ctrl+C won’t stop your program
• SystemExit — sys.exit() calls get swallowed
• MemoryError — System is out of memory but code continues
• Real bugs — Typos and logic errors get hidden

This makes programs hard to stop and hides real issues that should crash loudly.

Example

# ❌ Before
try:
    risky_operation()
except:
    pass

If risky_operation has a bug, you’ll never know. If the user presses Ctrl+C, nothing happens.

# ✅ After
try:
    risky_operation()
except Exception as e:
    logger.error("Operation failed", exc_info=e)

Exception excludes system-level errors like KeyboardInterrupt. The error is logged instead of silently swallowed.

What Unfault Detects

• except: without any exception class
• except: followed by pass (the worst pattern)

Auto-Fix

Unfault converts except: to except Exception as e: and adds logging if the body was empty or just pass.

Related Rules

• typescript.empty_catch
• go.bare_recover