Question

Code Review: Choose three of the programs you’ve written in this chapter and modify each one to comply with PEP 8: • Use four spaces for each indentation level. Set your text editor to insert four spaces every time you press TAB, if you haven’t already done so (see Appendix B for instructions on how to do this). • Use less than 80 characters on each line, and set your editor to show a vertical guideline at the 80th character position. • Don’t use blank lines excessively in your program files

Short answer

Refactor the code to meet PEP 8 guidelines through consistent indentation, line limits, and reduced blank lines.

Step-by-step solution

Adjust Indentation

Open the three programs that you have written. For each program, identify the lines of code and ensure that the indentation levels are consistent. If they are using tabs or a different number of spaces, replace them with four spaces for each indentation level. Modify your text editor’s settings to insert four spaces when you press the TAB key.

Limit Line Length

Review each line of code in your programs and make sure they have less than 80 characters. If a line exceeds this limit, break it into multiple lines. You can split long expressions, function arguments, or import statements to adhere to this rule. Also, configure your editor to highlight or mark the 80th character position as a guideline.

Minimize Excessive Blank Lines

Go through your programs and look for excessive blank lines. According to PEP 8 guidelines, functions and classes should be surrounded by a single blank line. Remove any additional blank lines within functions or between code sections. The goal is to make the code look clean and organized, without unnecessary blank space.

Key concepts

Python Indentation

Indentation in Python is crucial as it defines the code's structure and flow. Unlike some other programming languages that use specific characters to mark code blocks, Python relies on indentation. This keeps code clean and readable.
To comply with PEP 8, Python's style guide, you should use four spaces per indentation level. This consistency ensures not only uniformity across different codes but also clarity. PEP 8 advises against using tabs because different systems interpret tabs inconsistently, which can lead you to errors that are difficult to pinpoint.
When you press the TAB key in your code editor, it should insert four spaces instead of a tab character. You can easily adjust your text editor's settings to enable this feature, making your coding sessions more efficient and PEP 8 compliant.

• Check if your editor uses four spaces for Tabs.
• Avoid mixing tabs and spaces in your code.
• Consistency in indentation improves code readability.

Line Length Limitations

PEP 8 recommends keeping each line of code within a 79-character limit. This practice ensures your code remains readable without needing horizontal scrolling.
Long lines can be broken into multiple lines to fit this length limit. You might split function arguments, operators, or expressions, ensuring clarity is maintained even after line breaks.
Configuring your text editor to indicate the 80th character can act as a visual guideline. This helps you to visually keep track and organize your code within the recommended limit.

• Break longer lines for better readability.
• Avoid squeezing too much code into a single line.
• Use visual guidelines in editors to monitor line lengths.

Blank Lines Management

Proper management of blank lines contributes significantly to the readability and organization of your code. PEP 8 suggests using blank lines to separate top-level functions and class definitions.
A single blank line should suffice between these elements, ensuring that sections of your code are distinct but not cluttered. Excessive blank lines can disrupt the flow and clarity of your code structure.
Remove extra blank lines within functions or between sections of code. Keeping the recommended number of blank lines helps in distinguishing logically separate code sections without overwhelming the reader.

• Ensure single blank lines between functions and classes.
• Avoid excessive spacing which might confuse readers.
• Cohesive and organized code improves maintainability.