Why Every Python Script Has if __name__ == ‘__main__’: — And Why You Should Too
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Summary
The if name == ‘main’: is a Python code block that only executes when the script is run directly and not when it’s imported.
Understanding and using this line enhances code modularity and clarity.
It allows for the separation of concerns, enabling code reuse and Organized entry points, and provides flexibility in running tests within a module.
The code inside the block won’t run when the file is imported as a module, allowing for cleaner imports.
It can also be used to create command-line interfaces or for running example codeDemonstrated uses include running tests, demonstrating module usage, and creating command-line utilities, and providing a clear main execution flow in a script.
Following best practices, keeping modules clean and importable, and using this idiom as a script’s entry point are recommended.
Potential pitfalls include forgetting the check, leading to unexpected code execution on import, or overusing it in small scripts, adding unnecessary complexity.
Combining it with argparse and testing frameworks allows for sophisticated command-line tools and kept tests clean during imports, respectively.