Using Print

Resources

• Slides

The print(expression) statement in Python works in much the same way as the DISPLAY(expression) statement in pseudocode, but with one major difference. In pseudocode, the DISPLAY(expression) statement will print the value from the expression to the user, but it won’t add anything like a space or newline to the end. In Python, however, the print(expression) statement will add a newline to the end of the output by default. This means that multiple print(expression) statements will print on multiple lines. Let’s look at some examples!

Throughout this course, we’ll show many different code examples and their output here in the lab. To test them out, feel free to copy the code examples to a Python file and run it yourself. You can even tweak them to do something new and see how Python interprets different pieces of code. In the end, the best way to learn programming is to explore, and running these examples on your own is a great way to get started!

Multiple Lines

In Python, we can print multiple lines of output simply by using multiple print(expression) statements:

print("a")
print("b")
print("c")
print("d")

will result in this output:

a
b
c
d

We can also include a newline symbol \n in a print(expression) statement in Python. This will add a newline to the output, and then the print(expression) statement will add an additional newline at the end of the value that is printed:

print("one\ntwo")
print("three\nfour")

will produce this output:

one
two
three
four

Printing On the Same Line

What if we want to display multiple print(expression) statements on the same line? To do that, we must add an additional option to the print(expression) statement - the end option.

For example, the following code will produce output all on the same line:

print("Hello ", end="")
print("World!")

In this example, we set end to be an empty string "". When we run this program, we’ll get the following output:

Hello World!

In fact, in Python, the print(expression) statement is an example of a function in Python. Functions in Python are like procedures in pseudocode - when we call them, we write the name of the function, followed by a set of parentheses and then arguments separated by commas within the parentheses. So, in actuality, the expression in the print(expression) statement is just the first argument when we call the print function.

Therefore, the end option that we showed above is just a second argument that is optional - it simply let’s us choose what to put at the end of the output. By default, the end parameter is set to the newline symbol \n, so if we don’t provide an argument for end it will just add a newline at the end of the value.

We can set the value of end to be any string. If we want to include a space at the end of the output, we can add end=" " to the print function call.

In this course, we won’t spend much time talking about optional parameters and default values in Python functions, but it is important to understand that statements like print are actually just Python functions behind the scenes!