Differences

This shows you the differences between two versions of the page.

--- python_wiki:if_name_main [2016/11/30 22:00]
billdozor [if __name__ main]
+++ python_wiki:if_name_main [2019/05/25 23:50]
@@ Line 1: / Line 1: @@
-====== if __name__ main ======
-**General Information**
-Many python source files will have an interesting if statement around main(). This is why it exists.
-**Checklist**
-  * Python versions: 2 and 3
-----
-===== The Code =====
-<code python>
-if __name__ == '__main__':
-  main()
-</code>
-==== Explanation ====
-It may include other statements as well.
-This special if statement is checked by the python interpreter itself when it reads the source file.
-  * If the source is being run as the main program, it sets that source file as the special "__name__" variable to "__main__".
-  * If the source file is being imported from another module, the "__name__" variable will be set to the module's name instead.
-The entire reason behind this is:
-  * Sometimes modules are written to be executed directly.
-  * They could also be imported for use in another module.
-  * The main check allows for only the "main" code to execute if run directly and not if someone imports the module to call functions.