How to sum strings in Python

Sum strings in Python #

To sum strings in Python:

1. Call the str.join() method on an empty string.
2. Pass the iterable (e.g. a list of strings) to the join() method.
3. The result will be a string containing the items of the iterable.

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my_list = ['a', 'b', 'c']

# ✅ sum list of strings

# 👇️ without a separator
my_str = ''.join(my_list)
print(my_str)  # 👉️ 'abc'

# 👇️ with a space separator
my_str_2 = ' '.join(my_list)
print(my_str_2)  # 👉️ 'a b c'

# 👇️ with comma separator
my_str_3 = ', '.join(my_list)
print(my_str_3)  # 👉️ 'a, b, c'

The str.join method takes an iterable as an argument and returns a string which is the concatenation of the strings in the iterable.

If your list contains numbers, or other types, convert all of the values to string before calling join().

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my_list = ['a', 1, 'b', 2, 'c', 3]

my_str = ''.join(map(str, my_list))
print(my_str)  # 👉️ 'a1b2c3'

The map() function takes a function and an iterable as arguments and calls the function with each item of the iterable.

The string the join() method is called on is used as the separator between elements.

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my_list = ['a', 'b', 'c']


my_str = '-'.join(my_list)
print(my_str)  # 👉️ 'a-b-c'

If you need to join the list of strings with spaces, call the method on a string that contains a space.

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my_list = ['a', 'b', 'c']

# 👇️ with a space separator
my_str = ' '.join(my_list)
print(my_str)  # 👉️ 'a b c'

If you don't need a separator and just want to join the iterable's elements into a string, call the join() method on an empty string.

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my_list = ['a', 'b', 'c']

my_str = ''.join(my_list)
print(my_str)  # 👉️ 'abc'