Fixing TypeError: Coercing to Unicode - Converting List to String or Buffer in Python

This guide aims to provide a step-by-step solution to fix the TypeError: coercing to Unicode error that occurs while converting a list to a string or buffer in Python. This error is common when working with lists and strings, and understanding how to resolve it is crucial for developers working with data manipulation, parsing, or text processing.

Table of Contents

  1. Understanding the Error
  2. Step-by-Step Solution
  3. FAQ
  4. Related Links

Understanding the Error

The TypeError: coercing to Unicode error occurs when you try to concatenate a Unicode string with a non-Unicode string without explicitly converting the non-Unicode string to Unicode format.

For instance, consider the following code snippet:

unicode_string = u"Hello, world!"
non_unicode_string = "Python is awesome"

result = unicode_string + non_unicode_string

This code will generate the following error:

TypeError: coercing to Unicode: need string or buffer, list found

To fix this error, you must convert the non-Unicode string to Unicode format before concatenating.

Step-by-Step Solution

Follow these steps to resolve the TypeError: coercing to Unicode error by converting a list to a string or buffer in Python:

  1. Identify the non-Unicode string: Locate the non-Unicode string causing the error in your code.
non_unicode_string = "Python is awesome"
  1. Convert the non-Unicode string to Unicode format: Use the unicode() function to convert the non-Unicode string to Unicode format. Pass the string's encoding as the second argument to the function. By default, Python assumes the encoding is 'ascii'.
unicode_string = unicode(non_unicode_string, 'utf-8')
  1. Concatenate the strings: Now that both strings are in Unicode format, you can safely concatenate them.
result = unicode_string + u"Hello, world!"

Here's the complete code snippet:

unicode_string = u"Hello, world!"
non_unicode_string = "Python is awesome"

# Convert non-Unicode string to Unicode format
unicode_string2 = unicode(non_unicode_string, 'utf-8')

# Concatenate the Unicode strings
result = unicode_string + unicode_string2


1. What is Unicode and why is it important?

Unicode is a universal character encoding standard that assigns a unique number to every character in most of the world's writing systems. It enables us to consistently represent and manipulate text data in different languages, ensuring correct processing and display across various platforms and applications.

2. What is the difference between Unicode and ASCII?

ASCII (American Standard Code for Information Interchange) is a character encoding standard that uses 7 bits to represent 128 characters, including English letters, digits, and punctuation marks. On the other hand, Unicode is a superset of ASCII, using 8, 16, or 32 bits to represent over a million characters from various writing systems.

3. How do I identify if a string is in Unicode format?

In Python, a Unicode string is denoted with a u prefix. For example, u"Hello, world!" is a Unicode string, while "Hello, world!" is a non-Unicode string.

4. Can I use other encoding standards besides UTF-8 for converting non-Unicode strings to Unicode format?

Yes, you can use other encoding standards like 'iso-8859-1', 'cp1252', or any other supported by Python. However, UTF-8 is the most widely used and recommended encoding for Unicode strings.

5. Is there an alternative to the unicode() function in Python 3?

In Python 3, the str type represents Unicode strings, and there is no separate unicode type. To convert a non-Unicode string to a Unicode string in Python 3, use the str() function with the encoding parameter. For example, str(non_unicode_string, 'utf-8').

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