NameError: global name 'unicode' is not defined – in Python 3

Question:

I am trying to use a Python package called bidi. In a module in this package (algorithm.py) there are some lines that give me error, although it is part of the package.

Here are the lines:

# utf-8 ? we need unicode
if isinstance(unicode_or_str, unicode):
    text = unicode_or_str
    decoded = False
else:
    text = unicode_or_str.decode(encoding)
    decoded = True

and here is the error message:

Traceback (most recent call last):
  File "<pyshell#25>", line 1, in <module>
    bidi_text = get_display(reshaped_text)
  File "C:Python33libsite-packagespython_bidi-0.3.4-py3.3.eggbidialgorithm.py",   line 602, in get_display
    if isinstance(unicode_or_str, unicode):
NameError: global name 'unicode' is not defined

How should I re-write this part of the code so it works in Python3?
Also if anyone have used bidi package with Python 3 please let me know if they have found similar problems or not. I appreciate your help.

Asked By: TJ1

||

Answers:

Python 3 renamed the unicode type to str, the old str type has been replaced by bytes.

if isinstance(unicode_or_str, str):
    text = unicode_or_str
    decoded = False
else:
    text = unicode_or_str.decode(encoding)
    decoded = True

You may want to read the Python 3 porting HOWTO for more such details. There is also Lennart Regebro’s Porting to Python 3: An in-depth guide, free online.

Last but not least, you could just try to use the 2to3 tool to see how that translates the code for you.

Answered By: Martijn Pieters

You can use the six library to support both Python 2 and 3:

import six
if isinstance(value, six.string_types):
    handle_string(value)
Answered By: atm

Hope you are using Python 3 ,
Str are unicode by default, so please
Replace Unicode function with String Str function.

if isinstance(unicode_or_str, str):    ##Replaces with str
    text = unicode_or_str
    decoded = False
Answered By: M.J

If you need to have the script keep working on python2 and 3 as I did, this might help someone

import sys
if sys.version_info[0] >= 3:
    unicode = str

and can then just do for example

foo = unicode.lower(foo)
Answered By: Goblinhack

One can replace unicode with u''.__class__ to handle the missing unicode class in Python 3. For both Python 2 and 3, you can use the construct

isinstance(unicode_or_str, u''.__class__)

or

type(unicode_or_str) == type(u'')

Depending on your further processing, consider the different outcome:

Python 3

>>> isinstance(u'text', u''.__class__)
True
>>> isinstance('text', u''.__class__)
True

Python 2

>>> isinstance(u'text', u''.__class__)
True
>>> isinstance('text', u''.__class__)
False
Answered By: Friedrich

If a 3rd-party library uses unicode and you can’t change their source code, the following monkey patch will work to use str instead of unicode in the module:

import <module>
<module>.unicode = str
Answered By: user17242583

you can use this in python2 or python3

type(value).__name__ == 'unicode':
Answered By: lxgxx