Python format() Method

Beginner
5 min read
Updated: Nov 2026
3 examples
String
Decorative image with the word FORMAT

Definition

In Python, format() builds a new string by filling {} placeholders with values you pass.

You can use positional fields, named fields, or both. Format specifiers after a colon control width, precision, and alignment.

Syntax

Call format on a template string. Start with this line.

python
msg = "Hello, {}!".format(name)
CallWhat it does
"{} {}".format("Ada", "Lovelace")Fills positional fields.
"{name}".format(name="Ada")Fills a named field.

For one-off text, f-strings are often clearer. Keep format() for reusable templates.

Library declarations
python
str.format(*args, **kwargs) → str

Parameters

ParameterDescription
*argsOptional. Positional values for {} or {0}, {1}.
**kwargsOptional. Named values for {name} placeholders.

Return Value

Return ValueDescription
strA new string with placeholders replaced.

Python Examples

Example 1 — Positional Placeholders

Empty {} slots fill left to right from the arguments.

python
msg = "{}, {} and {}".format("red", "green", "blue")
print(msg)

# reuse / reorder with indexes
print("{1} then {0}".format("first", "second"))

How It Works

  1. Three empty braces. They take args 0, 1, and 2 in order.
  2. Result joins cleanly. Output is one readable sentence.
  3. Numbered fields. {1} and {0} pick arguments by index.
  4. Reorder without rewriting data. Handy for templates that share values.

Example 2 — Named Placeholders

Keyword arguments make templates easier to read and maintain.

python
template = "{user} has {points} points"
print(template.format(user="Ada", points=120))

# names can appear more than once
print("{x} + {x} = {y}".format(x=2, y=4))

How It Works

  1. Name each slot. {user} and {points} match keywords.
  2. Pass keywords in any order. Matching is by name, not position.
  3. Reuse a name. {x} appears twice with the same value.
  4. Clearer templates. Often better than many bare {} slots.

Example 3 — Format Specifiers

Control precision, alignment, and separators after the colon.

python
price = 1234.5
print("{:.2f}".format(price))
print("{:>10}".format("hi"))
print("{:,}".format(1000000))

# same ideas with an f-string:
# f"{price:.2f}"

How It Works

  1. .2f. Forces two decimal places (adds a trailing 0).
  2. >10. Right-aligns in a field 10 characters wide.
  3. ,. Inserts a thousands separator.
  4. Same mini-language. Specifiers also work inside f-strings.

Frequently Asked Questions

It replaces placeholders in a template with the values you provide.
A new str. The template is not modified.
f-strings embed values in the literal. format() keeps the template separate.
Use a specifier after a colon, such as {:.2f} or {:,}.
format_map(mapping) fills named placeholders from a mapping object.

Next: format_map()

Format a template using keys from a mapping/dict.

format_map() tutorial →

About the author

Mari Selvan M P
Mari Selvan M P 🔗

Developer, cloud engineer, and technical writer

  • Experience 12 years building web and cloud systems
  • Focus Full Stack Development, AWS, and Developer Education

I write practical tutorials so students and working developers can learn by doing—from databases and APIs to deployment on AWS.

AWS Certified Developer – Associate (Credly)

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