Python: Multiple Conditions and Loops

Name: Python: Multiple Conditions and Loops
Author: Jeremy Kurtz

How to handle multiple conditions and utilize loops.

Preview the first lesson free — get full access to all 9 lessons.

Course: On-Demand

In the last couple of lessons, we talked about the if statement and the if else statement. Now what we're going to do is code so that we can handle multiple conditions. We also want to code our if statements with user input. So the first thing we're going to do is open up our number 12 Python program and we're going to immediately save it as number 13. Once that's finished, I'm going to get rid of these a and b variables. And that gives us a little bit more of a clean slate to work with. In our case, we're going to write a small program that checks a user inputted percentage and outputs their grade based on that percentage. So a likely variable name would be great. And we're going to set that to int input, please enter a percentage and then we want to make sure we close the quotes and a couple of parentheses. Now I do want to point out that the reason we are using int here is since they're going to enter a percentage, which is a number, although this would certainly work as a string, we want to start getting into the habit of coding Python in the classical sense. Since it's a number, we are going to treat it as a number. So what int does is it converts the input into an integer. The other thing I want to point out is that when we initially did the if statement, it had parentheses around it. The reason why they're not there now is that since we're moving into more of a classical Python programming style, we'll learn that they are not only not necessary, but in multiple conditions, they can actually add to your chances of making a mistake. We will now eliminate those. And I'm going to say if grade is greater than or equal to 90 print, you got an A. Now, I'm going to take out what's in between the print statement on else, because the best thing we can do right now is test it to make sure that we don't have a problem. So I'm going to save it right now and run the module. So it's asking me for a percentage. I'm going to type in 91 and it says I got an A. So now I know my programming is sound. What I want to do though is I can look and see that the output is kind of bunched together. So what I would like to do is just put a backslash N and that'll take the cursor to the next line or entering. Once we have this, we are now going to use the else if or in Python, it's called L F E L I F. So if you've programmed before in other languages, most languages use else and if or they put them together as else if in Python, it's L if. So now we're going to say L F grade is greater than or equal to 80, then in my print statement, I can write U got a B. So now right below my L F statement, I'm going to copy the print statement from below and paste it in place underneath the L F. Now, what's important is that we remember that we want stuff to line up correctly. So this needs to be moved back, but in line with the ones above it. And what I'm going to do also is I'm going to just delete the final L statement because now what we can do is we can copy and paste our L F statement two more times to accommodate the grades. But first we need to go in here and change this because it doesn't make sense. So we'll say you got a B. Now we can copy and paste this two more times. And what I have to change is the letters and the percentages. So we have 90, 80, 70, and 60. And then we change this B to a C and this B to a D. Lastly, we have to put the L statement in. So the final L statement is else. Don't forget the colon and we're just going to write print, you got an F. So this is how the whole if L, if L system works. Now let's check it to make sure it runs and then we're going to talk about something.

Beginner Provider : Jeremy Kurtz 9 Lessons · 49m in English

Course Description

This course shows how “if” and “if-else” statements can guide your coding to handle multiple conditions. It also examines how to implement user input as a condition. You’ll be led through an example of these actions to better deal with multiple conditions. In turn, you’ll learn about loops programing structures that execute statements until a condition becomes true, focusing on the while loop, sentinel-controlled while loop, for loop, and nesting loops.

What You'll Learn

Use "if" and "if-else" statements to handle coding multiple conditions
Implement user input as a condition in your code
Identify and understand the different types of loops
Apply the while loop and the sentinel-controlled while loop
Build for loops and nest loops within one another
Apply the fundamental logic of conditions

Key Takeaways

"if" and "if-else" statements guide code to handle multiple conditions.
User input can be implemented as a condition within a program.
Loops are programming structures that execute statements until a condition becomes true.
The course covers the while loop, sentinel-controlled while loop, for loop, and nesting loops.
Worked examples are used to demonstrate handling multiple conditions.

Frequently Asked Questions

What does this Python course cover?

It covers using "if" and "if-else" statements to handle multiple conditions, implementing user input as a condition, and loop structures including the while loop, sentinel-controlled while loop, for loop, and nesting loops.

What skills will I gain from this course?

You will build skills in computer programming, conditional expressions, conditional statements, interactive programming, nested loops, and Python.

What is a loop as taught in this course?

The course describes loops as programming structures that execute statements until a condition becomes true.

How is the course structured?

The course is organized into lessons covering multiple conditions, loops, the while loop, the sentinel controlled value, the for loop, and nesting for loops, and it leads you through an example of handling multiple conditions.