What Is String Concatenation?

String concatenation is the process of joining two or more strings end-to-end to form a new, combined string. In Python, concatenation combines text values to create readable messages, dynamic output, or formatted strings. 

How to Concatenate Strings Using + Operator

The most common way to concatenate strings in Python is with the + operator. This operator takes two or more string values and returns a new string containing their text one after another.

Example:

Here, first + second joins "Hello" with "World" to create "HelloWorld". Because strings are immutable, this creates a new string.

Adding Space Between Strings

To insert a space or other character between concatenated strings, include it as part of the concatenation:

The literal " " adds a space between the text segments.

Concatenating Variables with Text

You can concatenate string variables with text content to build messages or dynamic output.

This generates a new string by combining text with the variable value.

Using += for Concatenation

You can also use augmented assignment (+=) to update a variable with additional text. Internally, this creates a new string and reassigns the variable.

This performs the same concatenation as text = text + " rocks".

Important Notes About Concatenation

  • Python creates a new string for each concatenation because strings are immutable. ([turn0search8])

  • If you repeatedly concatenate many strings (especially in loops), it may be less efficient than other techniques because each operation builds a new string object. ([turn0search8][turn0search9])

  • Concatenation works only with string data types; combining a string with a number without conversion causes an error.