Python print() and input(): Read User Input and Show Output

The Two Functions That Make Your Program Interactive

Most early Python programs follow the same shape: ask the user for something with input(), do something with the answer, and report back with print(). These two built-ins are how your code talks to the world.

Let's take them one at a time.

print(): Writing Output

At its simplest, print() writes a line of text to the terminal:

That outputs the word hello followed by a newline. The newline is what separates one print call from the next on screen.

You can pass several values in one call, and Python will put a space between them:

Output:

Name: Ada Age: 36

The values don't need to be strings. print calls str() on each argument, so you can mix types freely:

Changing the separator

If a space between values isn't what you want, use sep:

Changing the line ending

By default print appends a newline. Use end to change that — for example, to keep output on the same line:

end="" is the trick for building up a line piece by piece.

print Goes to stdout

By default, print writes to stdout (standard output) — the normal place terminal output appears. You can redirect it to stderr, a file, or any other file-like object with the file argument:

For formatted output — two decimal places, padded columns, commas in large numbers — use f-strings inside print:

input(): Reading From the User

input(prompt) stops the program, shows the prompt to the user, and waits. Whatever the user types — until they hit enter — comes back as a string.

Three things about input that bite newcomers:

It always returns a string

Even if the user types 42, what you get back is the string "42". You can't do arithmetic on it directly:

That's why you'll often see int(input(...)) or float(input(...)) inline. If the user types something that isn't a valid number, int() raises ValueError — which we'll handle properly in the chapter on exceptions.

The prompt is optional

If you don't pass a prompt string, input() waits silently, which is almost always the wrong call — the user has no idea what you're asking for. Always pass a clear prompt:

It strips nothing

Whatever the user types, including leading and trailing whitespace, comes back verbatim. If that matters for your logic, call .strip():

A Tiny Complete Program

Putting it all together — a few lines that ask the user for their info and print a small report:

Twelve lines. It reads top-to-bottom like instructions, not like code. That's the style these docs are trying to encourage.

What About print-Based Debugging?

You'll sometimes hear that "real developers use a debugger, not print statements." That's overstated. Print is a perfectly good debugging tool, especially for small scripts and quick experiments. Sprinkle print calls liberally while you're figuring something out, and remove them when you're done.

Two small quality-of-life tricks:

The = inside an f-string prints both the name and value, which saves a lot of print("name =", name) boilerplate.

Moving On

print and input give you a full conversational loop: ask, read, respond. The next chapter starts mixing in conditions — the if statement and the operators that decide what your program does based on the values it sees.