NameError: name 'unicode' is not defined in Python

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Borislav Hadzhiev

Last updated: Apr 20, 2022

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NameError: name 'unicode' is not defined in Python #

The Python "NameError name 'unicode' is not defined" occurs when using the unicode object in Python 3. To solve the error, replace all calls to unicode() with str() because unicode was renamed to str in Python 3.

nameerror name unicode is not defined

main.py
result = str('ABC') print(result) # 👉️ 'ABC'

Make sure to replace all occurrences of unicode with str in your code.

Alternatively, you can declare a unicode variable and set its value to the str class.

main.py
import sys if sys.version_info[0] >= 3: unicode = str print(unicode('ABC')) # 👉️ "ABC"

Our if statement checks if the version of the Python interpreter is greater or equal to 3, and if it is, we set the unicode variable to the str class.

Ever since Python 3, the language uses the concepts of text and binary data instead of unicode strings and 8-bit strings.

All text in Python is unicode, however encoded Unicode is represented as binary data.

You can use the str type to store text and the bytes type to store binary data.

main.py
my_text = 'hello' my_binary_data = bytes(my_text, 'utf-8') print(my_binary_data) # 👉️ b'hello'

In Python 3 you can no longer use u'...' literals for Unicode text because all strings are now unicode.

However, you must use b'...' literals for binary data.

You can use str.encode() to go from str to bytes and bytes.decode() to go from bytes to str.

main.py
my_text = 'hello' my_binary_data = my_text.encode('utf-8') print(my_binary_data) # 👉️ b'hello' my_text_again = my_binary_data.decode('utf-8') print(my_text_again) # 👉️ 'hello'

The str.encode() method is the opposite of bytes.decode() and returns a bytes representation of the unicode string, encoded in the requested encoding.

You can also use bytes(s, encoding=...) and str(b, encoding=...).

main.py
my_text = 'hello' my_binary_data = bytes(my_text, encoding='utf-8') print(my_binary_data) # 👉️ b'hello' my_text_again = str(my_binary_data, encoding='utf-8') print(my_text_again) # 👉️ 'hello'

The str class returns a string version of the given object. If an object is not provided, the class returns an empty string.

The syntax for using the bytes class is the same, except that a b prefix is added.

Conclusion #

The Python "NameError name 'unicode' is not defined" occurs when using the unicode object in Python 3. To solve the error, replace all calls to unicode() with str() because unicode was renamed to str in Python 3.

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