Summary: In this tutorial, we will learn what is join() in Python and how we can use it to join multiple strings.

What is join() in Python?

join() is a built-in string method in Python that joins the strings of an iterable such as list, set, tuple, etc into a single string.

It uses the string object on which it is invoked as the separator.

For example, in the following code, when we call join() on ‘#’ with a list of strings as a parameter, it concatenates all the strings of the list separated by ‘#’:

>>> l = ['pencil', 'programmer']
>>> '#'.join(l)

The syntax for join() method is:


join() Parameters

The join() method accepts an iterable as a parameter, joins the strings by the specified separator, and returns the concatenated string.

iterableRequiredAn iterable such as list, dict, set, string, tuple, etc with strings as returning elements.
Python join() method parameters

join() method joins the keys of the dictionary only if they are strings.

Examples using join()

Example 1: Join list of strings in Python

>>> l = ['', 'python-tutorials', 'join-method']
>>> separator = '/'
>>> separator.join(l)

Example 2: Join keys of dictionary in Python

>>> d = {'tom': 'cat', 'jerry': 'mouse'}
>>> separator = ' & '
>>> separator.join(d)
'jerry & tom'

Because the elements in the dictionary is not ordered, the join method joins the string in different order.

Example 3: Concatenate characters of the string separated by the given string.

>>> name = 'Rock'
>>> separator = '-'
>>> separator.join(name)

In summary, the string.join() method in Python concatenates the strings of an iterable by a separator into a single string object.

Leave a Reply