Tensorflow not include in the backend when using pip install '.[torch]'

[yinpeiqi]

System Info

I install the program successfully when using pip install -e .[torch].
However, I encounter the below issue when using pip install '.[torch]':

(omni) pqyin@proj54:/data2/pqyin/transformers$ python 
Python 3.13.9 | packaged by Anaconda, Inc. | (main, Oct 21 2025, 19:16:10) [GCC 11.2.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import transformers
Traceback (most recent call last):
  File "<python-input-0>", line 1, in <module>
    import transformers
  File "/home/pqyin/miniconda3/envs/omni/lib/python3.13/site-packages/transformers/__init__.py", line 768, in <module>
    sys.modules[__name__] = _LazyModule(
                            ~~~~~~~~~~~^
        __name__,
        ^^^^^^^^^
    ...<3 lines>...
        extra_objects={"__version__": __version__},
        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    )
    ^
  File "/home/pqyin/miniconda3/envs/omni/lib/python3.13/site-packages/transformers/utils/import_utils.py", line 1847, in __init__
    raise ValueError(
        f"Backend should be defined in the BACKENDS_MAPPING. Offending backend: {backend}"
    )
ValueError: Backend should be defined in the BACKENDS_MAPPING. Offending backend: tf

I check the module, I found that two backends tensorflow_text and tf are imported from {'models.bert.tokenization_bert_tf': {'TFBertTokenizer'}}, but tf and tensorflow_text are not in BACKENDS_MAPPING.
I found that the tokenization_bert_tf file is already deleted in the latest version, but install from pre-compiled whl file still contains the tokenization_bert_tf files. Thus incurred the import issue.

BTW, the deperated tokenization_bert_tf could be removed from type checking.

    # line 25 in bert.__init__.py
    from .tokenization_bert_tf import *

Who can help?

No response

Information

• The official example scripts
• My own modified scripts

Tasks

• An officially supported task in the examples folder (such as GLUE/SQuAD, ...)
• My own task or dataset (give details below)

Reproduction

Use pip install '.[torch]

Expected behavior

  File "/home/pqyin/miniconda3/envs/omni/lib/python3.13/site-packages/transformers/__init__.py", line 777, in <module>
    sys.modules[__name__] = _LazyModule(
                            ~~~~~~~~~~~^
        __name__,
        ^^^^^^^^^
    ...<3 lines>...
        extra_objects={"__version__": __version__},
        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    )
    ^
  File "/home/pqyin/miniconda3/envs/omni/lib/python3.13/site-packages/transformers/utils/import_utils.py", line 1847, in __init__
    raise ValueError(
        f"Backend should be defined in the BACKENDS_MAPPING. Offending backend: {backend}"
    )
ValueError: Backend should be defined in the BACKENDS_MAPPING. Offending backend: tensorflow_text

[Rocketknight1]

Yes, thank you for spotting that reference to TFBertTokenizer! I made a PR to remove it, hopefully that resolves any pip issues as well: #42182