Python Backslash
Summary: in this tutorial, you’ll learn about the Python backslash character as a part of a special sequence character or to escape characters in a string.
Introduction to the Python backslash
In Python, the backslash(\) is a special character. If you use the backslash in front of another character, it changes the meaning of that character.
For example, the t is a literal character. But if you use the backslash character in front of the letter t, it’ll become the tab character (\t).
Generally, the backslash has two main purposes.
First, the backslash character is a part of special character sequences such as the tab character \t or the new line character \n.
The following example prints a string that has a newline character:
print('Hello,\n World')Code language: PHP (php)
Output:
Hello,
World
The \n is a single character, not two. For example:
s = '\n'
print(len(s)) # 1Code language: PHP (php)
Second, the backslash (\) escape other special characters. For example, if you have a string that has a single quote inside a single-quoted string like the following string, you need to use the backslash to escape the single quote character:
s = '"Python\'s awesome" She said'
print(s)Code language: PHP (php)
Output:
"Python's awesome" She saidCode language: JavaScript (javascript)
Backslash in f-strings
PEP-498 specifies that an f-string cannot contain a backslash character as a part of the expression inside the curly braces {}.
The following example will result in an error:
colors = ['red','green','blue']
s = f'The RGB colors are:\n {'\n'.join(colors)}'
print(s)
Code language: PHP (php)
Error:
SyntaxError: f-string expression part cannot include a backslashCode language: JavaScript (javascript)
To fix this, you need to join the strings in the colors list before placing them in the curly braces:
colors = ['red','green','blue']
rgb = '\n'.join(colors)
s = f"The RGB colors are:\n{rgb}"
print(s)Code language: PHP (php)
Output:
The RGB colors are:
red
green
blue
Backslash in raw strings
Raw strings treat the backslash character (\) as a literal character. The following example treats the backslash character \ as a literal character, not a special character:
s = r'\n'
print(s)Code language: PHP (php)
Output:
\n
Summary
- Python backslash character (
\) is a special character used as a part of special sequence such as\tand\n. - Use the Python backslash (
\) to escape other special characters in a string. - F-strings cannot contains the backslash a part of expression inside the curly braces
{}. - Raw strings treat the backslash (\) as a literal character.