[Solved] Python SyntaxError: (unicode error) ‘unicodeescape’ codec can’t decode bytes in position 0-5: truncated \UXXXXXXXX escape

Introduction

The following error message is a common Python error, the “SyntaxError” represents a Python syntax error and the “unicodeescape” means that we made a mistake in using unicode escape character.

SyntaxError: (unicode error) 'unicodeescape' codec can't decode bytes in position 0-5: truncated \UXXXXXXXX escape

Simply to put, the “SyntaxError” can be occurred accidentally in Python and it is often happens because the \ (ESCAPE CHARACTER) is misused in a python string, it caused the unicodeescape error.

(Note: “escape character” can convert your other character to be a normal character.)

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SyntaxError Example

Let’s look at an example:

print('It's a nice day.')

Looks like we want to print “It’s a nice day.“, right? But the program will report an error message.

File "<stdin>", line 1
    print('It's a nice day.')
              ^
SyntaxError: invalid syntax

The reason is very easy-to-know. In Python, we can use print('xxx') to print out xxx. But in our code, if we had used the ' character, the Python interpreter will misinterpret the range of our characters so it will report an error.

To solve this problem, we need to add an escape character “\” to convert our ‘ character to be a normal character, not a superscript of string.

print('It\'s a nice day.')

Output:

It's a nice day.

We print it successfully!

So how did the syntax error happen? Let me talk about my example:

One day, I run my program for experiment, I saved some data in a csv file. In order for this file can be viewed on the Windows OS, I add a new code \uFFEF in the beginning of file.

This is “BOM” (Byte Order Mark), Explain to the system that the file format is “Big-Ending“.

I got the error message.

SyntaxError: (unicode error) 'unicodeescape' codec can't decode bytes in position 0-5: truncated \UXXXXXXXX escape

As mentioned at the beginning of this article, this is an escape character error in Python.

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Solutions

There are three solutions you can try:

• Add a “r” character in the right of string
• Change \ to be /
• Change \ to be \\

Solution 1: Add a “r” character in the beginning of string.

title = r'\uFFEF'

After we adding a r character at right side of python string, it means a complete string not anything else.

Solution 2: Change \ to be /.

open("C:\Users\Clay\Desktop\test.txt")

Change to:

open("C:/Users/Clay/Desktop/test.txt")

This way is avoid to use escape character.

Solution 3: Change \ to be \\.

open("C:\Users\Clay\Desktop\test.txt")

Change the code to:

open("C:\\Users\\Clay\\Desktop\\test.txt")

It is similar to the solution 2 that it also avoids the use of escape characters.

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The above are three common solutions. We can run normally on Windows.

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Reference

• https://stackoverflow.com/questions/37400974/unicode-error-unicodeescape-codec-cant-decode-bytes-in-position-2-3-trunca
• https://community.alteryx.com/t5/Alteryx-Designer-Discussions/Error-unicodeescape-codec-can-t-decode-bytes/td-p/427540

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