SyntaxError: (unicode error) 'unicodeescape' codec can't decode bytes in position 2-3: truncated \UXXXXXXXX escape

# SyntaxError: (unicode error) 'unicodeescape' codec can't decode bytes in position 2-3: truncated \UXXXXXXXX escape

The Python "SyntaxError: (unicode error) 'unicodeescape' codec can't decode bytes in position" occurs when we have an unescaped backslash character in a path.

To solve the error, prefix the path with r to mark it as a raw string, e.g. r'C:\Users\Bob\Desktop\example.txt'.

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  File "/home/borislav/Desktop/bobbyhadz_python/main.py", line 2
    file_name = 'C:\Users\Bob\Desktop\example.txt'
                                                  ^
SyntaxError: (unicode error) 'unicodeescape' codec can't decode bytes in position 2-3: truncated \UXXXXXXXX escape

Here is an example of how the error occurs.

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# ⛔️ SyntaxError: (unicode error) 'unicodeescape' codec can't decode bytes in position 2-3: truncated \UXXXXXXXX escape
file_name = 'C:\Users\Bob\Desktop\example.txt'

with open(file_name, 'r', encoding='utf-8') as f:
    lines = f.readlines()

    print(lines)

The path contains backslash characters which is the cause of the error.

The backslash \ character has a special meaning in Python. It is used as an escape character (e.g. \n or \t).

# Prefix the string with r to mark it as a raw string

One way to solve the error is to prefix the string with the letter r to mark it as a raw string.

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# ✅ Prefix string with r
file_name = r'C:\Users\Bob\Desktop\example.txt'

with open(file_name, 'r', encoding='utf-8') as f:
    lines = f.readlines()

    print(lines)

If the error persists, try to use a triple-quoted raw string instead.

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# ✅ Wrapped raw string in triple quotes
file_name = r'''C:\Users\Bob\Desktop\example.txt'''

with open(file_name, 'r', encoding='utf-8') as f:
    lines = f.readlines()

    print(lines)

You might also use the open() function directly, without the with statement.

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file_name = r'C:\Users\Bob\Desktop\example.txt'

my_file = open(file_name, 'r', encoding='utf-8')

lines = my_file.readlines()
print(lines)

my_file.close()

Prefixing the string with r works either way.

# Escape the backslash with a second backslash character

An alternative way to treat a backslash \ as a literal character is to escape it with a second backslash \\.

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# ✅ Escape each backslash with a second backslash
file_name = 'C:\\Users\\Bob\\Desktop\\example.txt'

with open(file_name, 'r', encoding='utf-8') as f:
    lines = f.readlines()

    print(lines)

We escaped each backslash character to treat them as literal backslashes.

Here is a string that shows how 2 backslashes only get translated into 1.

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my_str = 'bobby\\hadz'

print(my_str)  # 👉️ "bobby\hadz"

Similarly, if you need to have 2 backslashes next to one another, you would have to use 4 backslashes.

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my_str = 'bobby\\\\hadz\\\\com'

print(my_str)  # 👉️ "bobby\\hadz\\com"

# Using forward slashes instead of backslashes in paths

An alternative solution to the error is to use forward slashes in the path instead of backslashes.

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# ✅ Using forward slashes instead of backslashes
file_name = 'C:/Users/Bob/Desktop/example.txt'

with open(file_name, 'r', encoding='utf-8') as f:
    lines = f.readlines()

    print(lines)

A forward slash can be used in place of a backslash when you need to specify a path.

This solves the error because we no longer have any unescaped backslash characters in the path.

The error occurs because the \U character in the path is a Unicode code point.

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file_name = 'C:\Users\Bob\Desktop\example.txt'

If the 8 characters after \U are not numeric an error is raised.

Since backslash characters have a special meaning in Python, we need to treat them as a literal character by:

• prefixing the string with r to mark it as a raw string
• escaping each backslash with a second backslash
• using forward slashes in place of backslashes in the path

# The 3 possible solutions to the error

Here are the 3 possible solutions to the error.

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# ✅ Prefix string with r
file_name = r'C:\Users\Bob\Desktop\example.txt'

# ✅ Escaping each backslash with another backslash
file_name = 'C:\\Users\\Bob\\Desktop\\example.txt'

# ✅ Using forward slashes instead of backslashes
file_name = 'C:/Users/Bob/Desktop/example.txt'

If none of the suggestions works, try to use a triple-quoted raw string.

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file_name = r'''C:\Users\Bob\Desktop\example.txt'''

As this section of the docs states:

The backslash (\) character is used to escape characters that otherwise have a special meaning, such as newline, backslash itself, or the quote character.

Unless the string is prefixed with an r, escape sequences are interpreted as follows:

A backslash is also used as a continuation character.

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my_str = 'first \
second \
third'

print(my_str) # first second third

When a backslash is added at the end of a line, the newline is ignored.