Python 4: Functions
By the end of this lesson you should be able to:
1. Create and use your own functions.
2. Send data (parameters) to functions.
3. Explain what happens when a function calls itself
Functions allows the programmer to create useful blocks of code that can be called from any point in the program. There are many advantages to using functions:
· Compact code- Rather than writing the same code over and over again you can put it in a function and call it.
· Reusability If you have a function in one program you can copy and paste it into other programs.
· Testing- Large programs are hard to get right. It is much easier to debug a program that is written as a series of functions that can be individually tested.
Save each program in you unit 1 folder as a text document called A4Px where x is the program number. Then copy and paste it into the python interpreter. Use the # symbol in include your name and the program code at the top of your script.
Ex: #Tony Demello A4P1
Program 1 Count em Up
Write a function called countEmUp that takes two integers n1 and n2 as parameters and prints all of the integers from n1 to n2.
Bonus: Set up the function so that it returns a string representation of the sequence.
Test your function like this: countEmUp (2,10)
Program 2- Min of 3
Write a function called min3 that accepts 3 integers and returns the smallest value.
Test your function like this: print(The smallest number is, min3(5,15,2))
Program 3- Factorial
The factorial of an integer, n, is the product of all of the integers between 1 and n.
The factorial of 5=5 x 4 x 3 x 2 x 1
Write a function called fact that takes and integer, n, and uses a loop to calculate the factorial of n.
Test your program like this print( fact(5))
Program 4- Factorial Recursive Style
Write a function called factR that takes an integer n, and calculates the factorial of n recursively.
Test your program like this print( factR(5))
Show Mr.Kurz all 4 programs when you are finished.
Next up: Learning to program the GPIO