Babel doesn't recognize jinja2 extraction method for language support

Question

I'm adding language translation support to my project. The code is on Python and has jinja2 in the html files, and Javascript.

I'm trying to use Babel to do the translation, but it doesn't recognize the extraction method of jinja2. Maybe I'm using an incorrect name for it.

This is my ini file:

# Extraction from Python source files
[python: **.py]
# Extraction from Jinja2 template files
[jinja2: **.html]
# Extraction from JavaScript files
[javascript: **.js]
extract_messages = $._, jQuery._

And this is the error I receive;

C:\>python Babel-0.9.6/babel/messages/frontend.py extract --project=GV --version=1 --no-location -o locale\messages.pot -F babel.ini frontend te
mplates
extracting messages from frontend\__init__.py
INFO:babel:extracting messages from frontend\__init__.py
...
Traceback (most recent call last):
  File "Babel-0.9.6/babel/messages/frontend.py", line 1208, in <module>
    main()
  File "Babel-0.9.6/babel/messages/frontend.py", line 1107, in main
    return CommandLineInterface().run(sys.argv)
  File "Babel-0.9.6/babel/messages/frontend.py", line 651, in run
    return getattr(self, cmdname)(args[1:])
  File "Babel-0.9.6/babel/messages/frontend.py", line 912, in extract
    for filename, lineno, message, comments in extracted:
  File "c:\Python27\lib\site-packages\babel-0.9.6-py2.7.egg\babel\messages\extract.py", line 172, in extract_from_dir
    strip_comment_tags):
  File "c:\Python27\lib\site-packages\babel-0.9.6-py2.7.egg\babel\messages\extract.py", line 202, in extract_from_file
    strip_comment_tags))
  File "c:\Python27\lib\site-packages\babel-0.9.6-py2.7.egg\babel\messages\extract.py", line 271, in extract
    raise ValueError('Unknown extraction method %r' % method)
ValueError: Unknown extraction method 'jinja2'
Press any key to continue . . .

Any ideas? Thanks, Gadi

Martinson

Answer 1

I saw that your question was still unanswered. Your problem looks similar to what I got after reinstalling my development environment:

$ pybabel extract -F babel.cfg -o messages.pot .
extracting messages from admin.py
:
extracting messages from templates/404.html (extensions="jinja2.ext.autoescape,jinja2.ext.with_")
Traceback (most recent call last):
  File "/usr/local/bin/pybabel", line 9, in <module>
    load_entry_point('Babel==0.9.6', 'console_scripts', 'pybabel')()
  File "/usr/local/lib/python2.7/dist-packages/Babel-0.9.6-py2.7.egg/babel/messages/frontend.py", line 1107, in main
    return CommandLineInterface().run(sys.argv)
  File "/usr/local/lib/python2.7/dist-packages/Babel-0.9.6-py2.7.egg/babel/messages/frontend.py", line 651, in run
    return getattr(self, cmdname)(args[1:])
  File "/usr/local/lib/python2.7/dist-packages/Babel-0.9.6-py2.7.egg/babel/messages/frontend.py", line 912, in extract
    for filename, lineno, message, comments in extracted:
  File "/usr/local/lib/python2.7/dist-packages/Babel-0.9.6-py2.7.egg/babel/messages/extract.py", line 171, in extract_from_dir
    strip_comment_tags):
  File "/usr/local/lib/python2.7/dist-packages/Babel-0.9.6-py2.7.egg/babel/messages/extract.py", line 201, in extract_from_file
    strip_comment_tags))
  File "/usr/local/lib/python2.7/dist-packages/Babel-0.9.6-py2.7.egg/babel/messages/extract.py", line 270, in extract
    raise ValueError('Unknown extraction method %r' % method)
ValueError: Unknown extraction method 'jinja2'

It turned out that I had forgotten to install jinja2. Since the server environment had it installed I didn't notice it first. After installing jinja2 with:

$ sudo pip install jinja2

the extraction would complete:

$ pybabel extract -F babel.cfg -o messages.pot .
extracting messages from admin.py
:
extracting messages from test/item_tests.py
writing PO template file to messages.pot

Tucana

Just in case somebody else runs into the same problem: be sure to install jinja as an admin with 'sudo pip install Jinja2'. – Kirkland

Answer 2

Babel relies on the jinja2 entry point being set up in the egg info.

To workaround that, change this in you cfg file:

# Extraction from Jinja2 template files  
[jinja2: **.html]

to that:

# Extraction from Jinja2 template files  
[jinja2.ext:babel_extract[i18n]: **.html]

Spancel

I had another example that said to just add [extractors] jinja2 = jinja2.ext:babel_extract Is that the same or does it do something different? – Brenner

Answer 3

I had same problem. I solved it by upgrading setuptools from 20.7.0 to more fresh version:

sudo pip install --upgrade setuptools

Trauma

Today, in 2024, you saved my day!! – Cytolysin

Answer 4

I had same problem. In my case, I didn't install python-babel. So I install it by this command.

sudo apt-get python-babel

I solved the problem. But I'm not sure whya python-babel related with ValueError: Unknown extraction method 'jinja2'

Socialization

Answer 5

In my situation, I installed Babel weeks ago in my venv and everything worked great. After needing to reinstall my venv recently, I began having the same Traceback error specifically when it tried reading my html files in templates. Ultimately, I needed to install setuptools. Found the answer here.

Notum

While the information in your link may solve the OP's question, answers that rely heavily on links are discouraged for these reasons. Please consider updating your answer so that it is self-contained, with the minimum amount of code and instructions required to demonstrate how it works. Thanks – Dylane