A “String” is a sequence of characters that represents the text or data and “Characters” are symbols that we use to write and communicate, such as letters, numbers, punctuation marks, emojis, etc. “Unicode”, however, is a standard that defines how characters are represented by computers. It assigns a unique number (called a code point) to every character in every language and writing system in the world. For example, the character “A” belongs to the code point “U+0041”.
The main purpose of this article is to explain why and how to use the “u” prefix before the Python string.
What Does the “u” Prefix Before the String Mean in Python?
The specified strings prefixed with “u” indicate that it is a Unicode string literal. A literal is a way to write a value directly in the code without using variables or expressions and a Unicode string literal is a way to write a string that contains Unicode characters. For example, (u”Hello World”) is a Unicode string literal that contains 11 characters.
How to Use “u” Before a String in Python?
The simplest way to use “u” before a string in Python is to write it directly as part of the code. We just need to add the prefix “u” before single quotes (‘ ‘) or double quotes (” “) that enclose the characters.
Example 1: Adding “u” Before String in Python “2.x”
Specifying “u” before the string in Python “2.x” is illustrated in the below example code:
str2 = u'你好'
print(str1)
print(str2)
In the above code, the “u” prefix is used before the initialized strings to create Unicode string literals.
Output
Example 2: Adding “u” Before String in Python “3.x”
Python “3.x” introduced significant changes in string handling, thereby making it more streamlined and efficient, unlike Python “2.x”, Python “3.x” treats strings by default as Unicode strings. Therefore, the explicit “u” before string notation is no longer necessary which can be demonstrated, as follows:
str2 = '你好'
print(str1)
print(str2)
In the above code lines, the Unicode strings are initialized and printed to the output without using the prefix “u” before the strings.
Output
Conclusion
Python “2.x” uses the prefix “u” before the string notation in order to handle Unicode strings, but Python “3.x” uses Unicode by default, so the explicit “u” before the string notation is no longer necessary. The “u” before the string is important when working with legacy code or specific scenarios where compatibility or special character handling is required. This Python guide presented a complete guide on adding “u” before the string.
