The majority of programs that we write will need to be more than a single sequential path of execution. We usually work with data that isn’t always the same, and occasionally requires us to do different things based on that data. To achieve this we need to utilize conditionals. In this hands-on lab, we’ll work through the conditional logic for the popular interviewing Fizz-Buzz problem by creating a script that will prompt the user for a number and then print out either the number, “Fizz”, “Buzz”, or “FizzBuzz” depending on whether the number meets one of the Fizz-Buzz requirements.
To feel comfortable completing this lab you’ll want to know how to do the following:
* Utilize conditionals. Watch the “The `if` and `else` Statements” and “Handling Multiple Cases with `elif`” videos from the Certified Entry-Level Python Programmer Certification course.
* Handle user input. Watch the “The `input` Function” video from the Certified Entry-Level Python Programmer Certification course.
Learning Objectives
Successfully complete this lab by achieving the following learning objectives:
- Create the fizz-buzz-item.py Script, Make It Executable with python3.7, and Accept User Input
We’ll create a
fizz-buzz-item.pyright in our home directory (~), and we want to make sure that we can run it directly, so that we’re not completely tied to the path of ourpython3.7binary. We can do this by writing our shebang properly.Let’s create the file and set the shebang:
~/fizz-buzz-item.py
#!/usr/bin/env python3.7 # Python implementation hereWith the file created, we need to also make sure that it’s executable. We’ll do that using
chmod:$ chmod u+x ~/fizz-buzz-item.pyNext, we’ll prompt the user for a value, convert it to an
int, and store it off in a variable:~/fizz-buzz-item.py
#!/usr/bin/env python3.7 value = int(input("Enter an integer value: "))- Print “FizzBuzz” if the Value Is a Multiple of Three and Five
With the
valueread, we can create our conditional. Since we have a case that should trigger if the value is a multiple of three and five, then we’ll want that branch to be before the only multiple of three or only multiple of five branches, because either of those would also be true. Let’s create ourifstatement and print "FizzBuzz" if the condition is met, then add anelseto just print the value otherwise:~/fizz-buzz-item.py
#!/usr/bin/env python3.7 value = int(input("Enter an integer value: ")) if value % 5 == 0 and value % 3 == 0: print("FizzBuzz") else: print(value)Now we can run the script to make sure that what we’ve written up to this point is working properly:
$ ./fizz-buzz-item.py Enter an integer value: 15 FizzBuzz $ ./fizz-buzz-item.py Enter an integer value: 4 4 $- Print “Fizz” if the Value Is a Multiple of Three, and “Buzz” if it’s a Multiple of Five
To handle the other two cases of the Fizz-Buzz problem we’ll need to utilize
elifstatements for each of the individual comparisons that we used in ourifstatement. Let’s add those now:~/fizz-buzz-item.py
#!/usr/bin/env python3.7 value = int(input("Enter an integer value: ")) if value % 5 == 0 and value % 3 == 0: print("FizzBuzz") elif value % 3 == 0: print("Fizz") elif value % 5 == 0: print("Buzz") else: print(value)Now we can run the script to make sure that what we’ve written up to this point is working properly:
$ ./fizz-buzz-item.py Enter an integer value: 15 FizzBuzz $ ./fizz-buzz-item.py Enter an integer value: 4 4 $ ./fizz-buzz-item.py Enter an integer value: 6 Fizz $ ./fizz-buzz-item.py Enter an integer value: 10 Buzz $
