7 Powerful Ways to Concatenate Strings in Python

In Python there are multiple ways to concatenate strings, and this guide provides a comprehensive summary for future reference.

Plus operator

Use the + operator:

a, b = 'hello', ' world'
a + b  # 'hello world'

Comma operator

Use a comma, which works in print statements but creates a tuple when used in assignments:

a, b = 'hello', ' world'
print(a, b)  # hello  world

a, b  # ('hello', ' world')

Direct literals

Simply place string literals next to each other (with or without spaces):

print('hello' ' world')
print('hello''world')

Percent operator

Before Python 2.6 the % operator was the only formatting method and can also concatenate strings:

print('%s %s' % ('hello', 'world'))

format() method

The format method, introduced in Python 2.6, replaces % and can concatenate strings:

print('{}{}'.format('hello', ' world'))

join() method

The built‑in join method concatenates an iterable of strings:

print('-'.join(['aa', 'bb', 'cc']))

f‑string

Python 3.6 introduced formatted string literals (f‑strings), an evolution of % and format:

aa, bb = 'hello', 'world'
f'{aa} {bb}'  # 'hello world'

Multiplication operator

Use * to repeat a string:

aa = 'hello '
aa * 3  # 'hello hello hello '

Summary

For a small number of strings , the + operator is recommended. If performance matters and you are on Python 3.6+, use f‑strings for better readability.

For a large number of strings , prefer join or f‑strings, depending on your Python version and readability requirements.

Reference: “You don’t know Python | Secrets of string concatenation” (https://juejin.im/post/5b350624f265da5954426713)