Python Functions
- 1. Python Functions ● Define functions ● Passing arguments to Function ● Return a value from function ● Scope of Objects ● Default arguments ● Positional and keyword arguments ● Variable length arguments
- 2. Functions Piece of reusable code Solves particular task Call function instead of writing code yourself
- 4. Syntax of Function Mohammed Sikander 4
- 6. Function Call Once we have defined a function, we can call it from another function, program or even the Python prompt. To call a function we simply type the function name with appropriate parameters. Calling the Function my_function()
- 7. Square function:Take one arguments and prints its square
- 8. Square function:Take one arguments and returns its square
- 10. Scope and Lifetime of variables Scope of a variable is the portion of a program where the variable is recognized. Parameters and variables defined inside a function is not visible from outside. Hence, they have a local scope. Lifetime of a variable is the period throughout which the variable exits in the memory. The lifetime of variables inside a function is as long as the function executes. They are destroyed once we return from the function. Hence, a function does not remember the value of a variable from its previous calls.
- 14. Default Arguments Function arguments can have default values in Python. We can provide a default value to an argument by using the assignment operator (=).
- 15. Default Arguments In this function, the parameter amount does not have a default value and is required (mandatory) during a call. On the other hand, the parameter discountPercentage has a default value of 0. So, it is optional during a call. If a value is provided, it will overwrite the default value. Any number of arguments in a function can have a default value.
- 16. Default Arguments Once we have a default argument, all the arguments to its right must also have default values. SyntaxError: non-default argument follows default argument
- 18. Positional argument cannot follow keyword argument
- 19. Variable number of arguments
- 20. Functions as Objects ● Although functions are created differently from normal variables, functions are just like any other kind of value. ● They can be assigned and reassigned to variables, and later referenced by those names.