cryptography+fernet+partially+initialized

Not specified by the original author.

ImportError: cannot import name 'Fernet' from partially initialized module 'cryptography.fernet'

TL;DR: you have a file named cryptography.py (or a folder named cryptography) in your working directory, and Python imports it instead of the real package. Rename your file to something else, delete any cryptography.pyc or pycache leftovers, and the import works again.

ImportError: cannot import name 'Fernet' from partially initialized module 'cryptography.fernet' (most likely due to a circular import)

The fix

1. Find the shadowing file:

ls cryptography.py
python -c "import cryptography; print(cryptography.__file__)"

Success check: the printed path points at site-packages, not your project folder. If it points at your folder, that file is the problem.

2. Rename your file to anything else, for example crypto_helpers.py, and update any imports of it.
3. Clear stale bytecode:

rm -f cryptography.pyc
rm -rf __pycache__

4. Verify:

python -c "from cryptography.fernet import Fernet; print('ok')"

Expected output: ok.

Agent? Search Vectle for more: curl -s 'https://vectle.com/api/v1/search?q=cryptography+fernet+partially+initialized'

When this applies

• The phrase "partially initialized module" appears in the error.
• import cryptography resolves to a file inside your own project.
• The same code works when run from a different directory.

When it does NOT apply

• The error is No module named 'cryptography', which means it is not installed at all.
• The error names a missing name like default_backend, which is a version problem, not shadowing.

Why this happens

Python puts the script's directory first on sys.path. A local cryptography.py wins over the installed package, so cryptography.fernet resolves inside your half-imported file, which has no Fernet in it yet. This is a circular import of your own making, and renaming the file is the only real fix. Prefixing local module names (my_crypto.py) avoids it permanently.

Compatibility

Any Python version, any cryptography version. The trigger is the filename, not the library.

This is the classic module-shadowing trap and it bites cryptography users regularly: naming any file in the working directory cryptography.py (or having a local folder named cryptography) makes from cryptography.fernet import Fernet import the local file instead of the installed package, and Python reports the partially-initialized-module ImportError. The fix is always the same, rename the shadowing file and delete any cached bytecode, then the real package imports cleanly. The same shadowing pattern causes identical errors for jwt.py, Crypto.py and other single-word package names.

Not specified by the original author.

TL;DR: The key is missing, wrong, expired, or not visible to the process. This error is not retryable, so retry loops will not save you. Try the provider's own playground or CLI with the same key to isolate LangChain from the key. Proxy or non-standard endpoint?

The error

langchain_core.exceptions.ModelAuthenticationError

The fix

1. Is the variable set in the actual process environment? Print it (or its presence) from inside the running process. dotenv files that load after the model is constructed, containers that did not get the env file, and notebooks with a stale kernel are the classics.
2. Is the name right? OPENAIAPIKEY, ANTHROPICAPIKEY. A typo'd variable name looks exactly like a missing key.
3. Is the key valid and current? Keys get rotated and revoked. Try the provider's own playground or CLI with the same key to isolate LangChain from the key.
4. Proxy or non-standard endpoint? Make sure the custom endpoint does not expect a different auth scheme.
5. Set the variable before the model is constructed, or pass the key explicitly to the model class.
6. In JS, the same condition surfaces as the MODELAUTHENTICATION error code on the thrown error's `lcerror_code`.

When to use this

• You are seeing this exact error message; match the block above, not just part of it.
• The failing call matches the scenario in the title: ModelAuthenticationError.
• You want the fastest verified fix before digging through logs.

When not to use this

• Your error text differs from the block above; close cousins often have different causes.
• The stack trace points at a different component than the one in the title.
• You already applied this fix and the error persists; look for a second cause instead of reapplying.

Compatibility

• Not pinned to a specific version; follows current ModelAuthenticationError behavior.

Also seen as

• lc_error_code
• `d variable name looks exactly like a missing key.

3. Is the key valid and current? Keys get rotated and revoked. Try the provider`

Error catalog entry grounded in the official model exceptions and error docs, verified 2026-09-26. Models: https://docs.langchain.com/oss/python/langchain/models ; error page: https://docs.langchain.com/oss/python/langchain/errors/MODEL_AUTHENTICATION

Not specified by the original author.

ImportError: cannot import name 'encode' from partially initialized module 'jwt'

TL;DR: a file named jwt.py in your project shadows PyJWT. Rename your file, delete pycache, and the import works. Check with python -c "import jwt; print(jwt.__file__)": if it points at your project, that file is the culprit.

ImportError: cannot import name 'encode' from partially initialized module 'jwt' (most likely due to a circular import)

The fix

1. Confirm the shadowing:

python -c "import jwt; print(jwt.__file__)"

Success check: the path is under site-packages. If it is your project folder, keep going.

2. Rename jwt.py to something descriptive like token_utils.py and fix any local imports of it.
3. Clear bytecode:

rm -rf __pycache__ jwt.pyc

4. Verify:

python -c "from jwt import encode; print('ok')"

Expected output: ok.

Agent? Search Vectle for more: curl -s 'https://vectle.com/api/v1/search?q=pyjwt+partially+initialized+module'

When this applies

• The error says "partially initialized module 'jwt'".
• The same code works from any other directory.
• You have a jwt.py somewhere on sys.path.

When it does NOT apply

• The error is AttributeError about a missing encode, which is the wrong-package problem.
• The error is No module named 'jwt', which means PyJWT is not installed.

Why this happens

The script directory comes first on sys.path, so a local jwt.py wins over site-packages. Python starts importing your file, your file (or something it triggers) does from jwt import encode, and the half-built local module has no encode yet. Never name project files after third-party top-level packages.

Compatibility

All Python and PyJWT versions. The trigger is the filename.

A file named jwt.py in the working directory shadows the installed PyJWT package: Python imports the local file first, and from jwt import encode then fails with the partially-initialized-module ImportError because the local file is still being imported. The itsourcecode troubleshooting guide for the jwt encode failures explicitly calls out checking for a local jwt.py via checking jwt.file as the second fix after the wrong-package uninstall. Renaming the file and clearing pycache resolves it immediately.