This document discusses function parameters in Python. It explains that parameters hold the values passed into a function as arguments. Parameters act as variables that accept the values passed during a function call. Functions can have multiple parameters, and the number and order of arguments passed must match the function definition. Arguments are passed by value, so changes to a parameter do not affect the original argument. A function can return multiple values using return, and functions themselves can be passed as parameters to other functions.

1. Function Parameters

2. Sending Data into a Function
 Can pass values into a function at time of call:
c = pow(a, b)
time.sleep(2)
 Values passed to function are arguments
 Variables in a function that hold the values
passed as arguments are parameters

3. A Function with a Parameter Variable
def displayValue(num):
print("The value is ", num)
The integer variable num is a parameter.
It accepts any value passed to the function.

4. Parameter Passing Example
(4)

5. Function Call Notes
 Value of argument is copied into parameter when
the function is called
 A parameter’s scope is the function which uses it
 Function can have multiple parameters

6. Passing Multiple Arguments
When calling a function and passing multiple arguments:
 The number of arguments in the call must match the prototype and
definition
 The first argument will be used to initialize the first parameter, the
second argument to initialize the second parameter, etc.

7. Passing Multiple Arguments Example

8. Passing Data by Value
 Pass by value: when an argument is passed to a function, its value is
copied into the parameter.
 Changes to the parameter in the function do not affect the value of the
argument
 Example: val = 5
evenOrOdd(val)
 evenOrOdd can change variable num, but it will have no effect on variable
val
5
val
argument in
calling function
5
num
parameter in
evenOrOdd function

9. Returning Multiple Values
 The python return statement unlike other languages can return
multiple values
 Code: Function call with multiple return values
 var1, var2, … = function()

10. Functions as Parameters
 Parameters can be functions
 Remember a function can return a value (transitive property)