Python format() Method: Precisely Format Strings | Syntax, Examples & Use Cases

Example 1: Basic Usage of format() Method

Let’s start with a simple example to see how this actually works in practice.

You’ll notice how quickly it replaces manual string building with something much cleaner.

Example 1.1: Basic Positional Formatting

In the simplest form, placeholders {} are replaced in the same order as values passed to the format() method.

message = "Hello, {}!".format("Alex")
print(message)

# Output:
# Hello, Alex!

Explanation: The placeholder {} is replaced with the value “Alex”, creating a new formatted string.

Why this matters: This is the simplest way to use format(), and it already makes your output look cleaner compared to manual string building.

Example 1.2: Multiple Placeholders Example

You can insert multiple values into a string by using multiple placeholders.

name = "Alice"
age = 30
print("Name: {}, Age: {}".format(name, age))

# Output:
# Name: Alice, Age: 30

Explanation: Each placeholder is filled in order with the corresponding values passed to format().

Why this matters: In real-world programs, you often need to display multiple values together. This example shows how to combine them in a structured and readable format.

Example 2: Using Positional Indexing

Sometimes, relying on position alone isn’t enough. That’s where indexing becomes useful.

Example 2.1 — Reusing Values by Index

print("First: {0}, Second: {1}, Again First: {0}".format("apple", "banana"))

# Output:
# First: apple, Second: banana, Again First: apple

Explanation: Index {0} refers to “apple” and {1} refers to “banana”. The same value can be reused multiple times.

Example 2.2 — Reordering Values

report = "{0} bought {2} apples and {1} bananas.".format("John", 5, 10)
print(report)

# Output:
# John bought 10 apples and 5 bananas.

Explanation: The indexes rearrange the values, allowing flexible placement regardless of their original order.

Example 3: Using Named Placeholders

When your strings get longer, using names instead of numbers makes things much easier to read and maintain.

info = "Name: {name}, Age: {age}, City: {city}".format(
    name="Maya", age=29, city="Delhi"
)
print(info)

# Output:
# Name: Maya, Age: 29, City: Delhi

Explanation: Each placeholder is matched with a named argument, making the string more readable and easier to maintain.

Example 4: Formatting Numbers, Precision & Alignment

Beyond simple replacements, format() also gives you control over how values actually appear in the output.

Controlling Float Precision

pi = 3.1415926535
print("Pi up to 2 decimal places: {:.2f}".format(pi))

# Output:
# Pi up to 2 decimal places: 3.14

Explanation: The format specifier {:.2f} limits the float to 2 decimal places.

Padding and Text Alignment

print("{:<10} {:^10} {:>10}".format("Left", "Center", "Right"))

# Output:
# Left       Center      Right

Explanation: < left-aligns, ^ centers, and > right-aligns text within a fixed width.

Adding Thousand Separators and Combining Features

print("Salary: {:,}".format(2500000))

output = "User {name} has {points:,} points and a rating of {rating:.1f}.".format(
    name="Ravi", points=45300, rating=4.678
)
print(output)

# Output:
# Salary: 2,500,000
# User Ravi has 45,300 points and a rating of 4.7

Explanation: The comma , adds thousand separators, and {:.1f} limits the rating to one decimal place.