4. FINDING CODE SMELL S¶
Code that causes a program to crash is obviously wrong, but crashes aren’t the only indicator of issues in your programs. Other signs can suggest the presence of more subtle bugs or unreadable code. Just as the smell of gas can indicate a gas leak or the smell of smoke could indi- cate a fire, a code smell is a source code pattern that sig- nals potential bugs. A code smell doesn’t necessarily mean a problem exists, but it does mean you should investigate your program.
This chapter lists several common code smells. It takes much less time and effort to prevent a bug than to encounter, understand, and fix a bug later. Every programmer has stories of spending hours debugging only tofind that the fix involved changing a single line of code. For this reason, even a whiff of a potential bug should give you pause, prompting you to double-check that you aren’t creating future problems.
Of course, a code smell isn’t necessarily a problem. Ultimately, whether to address or ignore a code smell is a judgment call for you to make.
- 4.1. Duplicate Code
- 4.2. Magic Numbers
- 4.3. Commented-Out Code and Dead Code
- 4.4. Print Debugging
- 4.5. Variables with Numeric Suffixes
- 4.6. Classes That Should Just Be Functions or Modules
- 4.7. List Comprehensions Within List Comprehensions
- 4.8. Empty except Blocks and Poor Error Messages
- 4.9. Code Smell Myths
- 4.10. Summary