Defining Functions of Your Own# A First Function Definition The Birthday Problem Defining a Function Calling a Function Calling Multiple Times Multiple Function Definitions Example: Two Birthday Songs Order of Definitions and Calls Function Parameters Defining a Parameter Calling with an Argument How it Works Parameters vs. Arguments Multiple Function Parameters Example: Addition Keyword Arguments Default Values Returned Function Values The return Statement Example: Weekly Wages Functions Without return Early Return Two Roles: Writer and Consumer of Functions The Writer The Consumer The Contract Separation of Concerns Local Scope Local Variables Why Local Scope? How Python Looks Up Names Using Global Variables (Avoid When Possible) Bad Scope Example Library Modules Importing a Module The math Module The random Module Selective Import How Python Finds Modules Writing Your Own Module Chapter Review Questions
