default is used when option is not provided. const is used when option is provide, but no value is given.
For example, if we have an arg ‘–bookname’ for test.py, then test.py will use default name, test.py –bookname will use const name.
default is used when option is not provided. const is used when option is provide, but no value is given.
For example, if we have an arg ‘–bookname’ for test.py, then test.py will use default name, test.py –bookname will use const name.