09. The print toolkit

Since Chapter 07, print has been your window into a running program. It does more than show one string. This chapter collects the tricks you use from here on: several values at once, controlling what goes between them, and blank lines.

Several values, separated by spaces

Separate values with commas to pass print more than one. It prints them on one line with a space between each:

print("Name", "Level", "HP")
print("Keiko", 7, 95)

Output:

Name Level HP
Keiko 7 95

Two things to notice. Values can be different types — strings and numbers mixed freely. And numbers need no quotes; 7 is a number, "7" a string.

Controlling the separator

By default print uses a single space between values. You can change that with the sep keyword argument:

print("Name", "Level", "HP", sep=", ")
print("Keiko", 7, 95, sep=", ")

Output:

Name, Level, HP
Keiko, 7, 95

Set sep="" (empty string) to put nothing between the values.

Controlling the ending

By default print puts a new line at the end. You can change that with the end keyword argument:

print("Loading", end="")
print("... done")

Output:

Loading... done

Both calls land on the same line because the first one did not end with a new line.

F-strings: building a line exactly

For full control of spacing and layout, use an f-string. Put f before the opening quote and use {} curly braces to drop a value into the text:

name = "Keiko"
hp = 95
level = 7
print(f"{name} has {hp} HP at level {level}")

Output:

Keiko has 95 HP at level 7

With an f-string there is no automatic separator — you decide what goes between the pieces, spaces included. F-strings also handle numbers directly; no conversion needed.

Commas or f-strings: which to use?

Both are fine. A rough guide:

• Commas: quickest when space-separated output is good enough (debugging, quick checks).
• F-strings: for a polished sentence with exact spacing and punctuation, like "Keiko has 95 HP".

name = "Keiko"
hp = 95
print(name, "has", hp, "HP")           # Keiko has 95 HP
print(f"{name} has {hp} HP")           # Keiko has 95 HP

The second is more readable when the output needs to look like a sentence.

Blank lines

print() with nothing inside prints an empty line. Use it to space out output so it reads more easily:

print("Chapter 1")
print()
print("Chapter 2")

Output:

Chapter 1

Chapter 2

A number is not its text

One last thing. These two look the same but are different types:

print(7)        # the number seven
print("7")      # a string containing the character 7

Both display 7, but one is a number and the other text — different types. Python can sometimes bridge the gap, but do not count on it. You meet types in the next part. For now, just know a number and its text version differ even when they look identical. It matters in the input chapter, where what the user types arrives as text.

Homework

Homework files are in exercises/09/homework/.

Keiko has 95 HP at level 7

Stuck or finished? Open the homework solutions page.