What is String Concatenation?

String concatenation is the operation of joining two or more string values end-to-end. In Python, you can join strings with the ‘+’ operator. It doesn’t add like numerical values but glues the strings together, forming a more extended string.

1str1 = "Hello"
2str2 = "World"
3concatenated_str = str1 + " " + str2


Hello World

The function print() displays the result on the console: “Hello World”. It’s because the string variables str1 and str2 were concatenated, with an additional string containing just a space " " in the middle.

Joining Multiple Strings

It’s also possible to join or concatenate multiple strings at once.

1str1 = "Hello"
2str2 = "Code"
3str3 = "Bay"
4concatenated_str = str1 + " " + str2 + " " + str3


Hello Code Bay

Notice how each string is separated by a " " in the console.

Concatenation with Other Data Types

Be cautious when trying to concatenate strings with other data types. Python doesn’t support the concatenation of strings with non-strings. For example, trying to concatenate a string with a number will result in a TypeError.

1str1 = "Hello "
2num = 5
3print(str1 + num)

The code snippet above will result in TypeError: can only concatenate str (not “int”) to str.

To concatenate a number to a string, the number must be converted into a string first with the str() function.

1str1 = "Hello "
2num = 5
3print(str1 + str(num))


Hello 5

Now the number 5 was successfully concatenated to the “Hello " string after being converted to a string.

Did you know?

String concatenation is a common operation in Python programming, especially when dealing with user input, file reading/writing, and generating output.