ModuleNotFoundError No module named pip install

Not specified by the original author.

TL;DR

no module named bs4 means nothing named bs4 is installed in the Python that is running your code. The fix is to install the real library under its PyPI name: run python -m pip install beautifulsoup4 (the import name is bs4, the install name is beautifulsoup4), then confirm with python -c "import bs4; print(bs4.version)". If it still fails, you installed into a different interpreter or environment than the one running the script.

ModuleNotFoundError: No module named 'bs4'

Use this when

• The traceback is exactly ModuleNotFoundError: No module named 'bs4', or a log tail shows just no module named bs4
• A fresh machine, container, venv, or CI runner where requirements were never installed
• The same script works on your laptop but fails in Docker or CI

Not for this skill when

• ImportError saying cannot import name 'BeautifulSoup' from 'bs4': something IS installed but it is the stub or a shadow file, a different problem
• FeatureNotFound: bs4 imported fine and a parser is missing instead
• The missing module is a different one (socks, nacl, tokenizers): same shape, different install name; see Related skills

Steps

1. Install beautifulsoup4 into the interpreter you actually run:

python -m pip install beautifulsoup4

Expected: Successfully installed beautifulsoup4 with a 4.x version. Using python -m pip guarantees the package lands in the same interpreter that runs your script.

2. Confirm the import in that same interpreter:

python -c "import bs4; print(bs4.__version__)"

Expected: prints a version like 4.12.3.

3. If it still fails, check for a second Python:

which python
which python3
pip --version

Expected: the paths agree. When pip belongs to a different Python than python, installs go missing; repeating step 1 with python -m pip makes the mismatch disappear.

4. Pin it so it does not come back. Add beautifulsoup4 to requirements.txt, your pyproject dependencies, or your Dockerfile install step.

Expected: a fresh environment built from those files imports bs4 with no error.

Variant phrasings

ModuleNotFoundError: No module named 'bs4'

The full traceback form of this query, with the exception name and quotes. Same missing package, same fix: python -m pip install beautifulsoup4.

no module named 'bs4'

The quoted form, as pasted from a traceback tail or a log. Same fix as above.

works locally, fails in docker or CI

Your local environment has beautifulsoup4 (often pulled in by something else); the image or runner does not. Step 4 is the durable fix: declare the dependency in the file the environment is built from.

Root cause

The distribution name and the import name differ: you pip install beautifulsoup4 but you import bs4. People who guess pip install bs4 get the 0.0.1 placeholder package instead, which converts this error into the nastier cannot import name 'BeautifulSoup' one. The other classic cause is installing into one Python while running another, which is why python -m pip is the reliable spelling.

Edge cases

• Do NOT pip install bs4. That installs the placeholder and makes the next error harder.
• Conda users: conda install beautifulsoup4 from defaults or conda-forge works the same.
• In Docker, make sure the pip install layer actually ran; a cached layer from before beautifulsoup4 was added to requirements silently skips it.
• A local file named bs4.py in your project folder shadows the real package; rename it if the import resolves to your file.

Tool compatibility

All beautifulsoup4 4.x on Python 3. The PyPI name has been beautifulsoup4 since the beginning; the top-level import has always been bs4. pip, conda, Docker, and CI runners all follow the same rule.

Related skills

• ModuleNotFoundError: No module named 'socks' (same import-name vs install-name trap, in requests): https://vectle.com/skills/sklFlB19WyD4leM499zch4jQ
• atlassian-python-api fails on import with ModuleNotFoundError: No module named 'bs4': https://vectle.com/skills/skl_M4NYvQlI7UbHhNAS16Vc1w

Provenance

Built from a documented GitHub issue where this error was fixed by installing beautifulsoup4, linked in the evidence.

In gh:jarrettr/stretch#36 a user hit ModuleNotFoundError: No module named 'bs4' trying to run the stretch project, and the fix was installing the project's dependencies including beautifulsoup4 (the PyPI name) rather than anything named bs4. This name mismatch is the single most common cause of the report. Source: https://github.com/jarrettr/stretch/issues/36

Not specified by the original author.

ModuleNotFoundError: No module named 'OpenSSL'

TL;DR: the distribution is called pyOpenSSL but the module is OpenSSL. Run pip install pyOpenSSL and the import works.

ModuleNotFoundError: No module named 'OpenSSL'

The fix

pip install pyOpenSSL

Verify:

python -c "from OpenSSL import SSL; print('ok')"

Expected output: ok.

Agent? Search Vectle for more: curl -s 'https://vectle.com/api/v1/search?q=pyOpenSSL+No+module+named+OpenSSL'

When this applies

• from OpenSSL import SSL fails on a fresh virtualenv, container, or CI runner.
• You ran pip install OpenSSL (no such distribution) or never installed it.
• urllib3 1.x PyOpenSSL injection code that imports OpenSSL.

When it does NOT apply

• module 'lib' has no attribute 'X509_V_FLAG_CB_ISSUER_CHECK', which is the pyOpenSSL/cryptography version mismatch.
• Import errors for _cffi_backend, which is the cffi backend problem.

Why this happens

Distribution names and import names are independent on PyPI, and pyOpenSSL is one of the classic mismatches. pip cannot guess from the import statement, so the ModuleNotFoundError persists until you learn the real distribution name. The PyPI page always lists the exact install command.

Compatibility

pyOpenSSL 23+. Needs the cryptography package, which pip installs automatically.

The module is OpenSSL but the distribution is pyOpenSSL, so guessing the pip name from the import fails. The pyOpenSSL project page documents pip install pyOpenSSL as the install command. This is the same distribution-name versus import-name mismatch as python-jose and Flask-Bcrypt, and the fix is the same one-line install.

Not specified by the original author.

ModuleNotFoundError: No module named 'truststore'

TL;DR: truststore is not in the stdlib. Run pip install truststore (Python 3.10+ required) and the import works.

ModuleNotFoundError: No module named 'truststore'

The fix

pip install truststore

Verify:

python -c "import truststore; print('ok')"

Expected output: ok.

Note: truststore needs Python 3.10+. On older Pythons the install succeeds but nothing works; upgrade Python instead.

Agent? Search Vectle for more: curl -s 'https://vectle.com/api/v1/search?q=truststore+No+module+named'

When this applies

• Adding OS certificate-store support to requests, httpx, or aiohttp.
• Fresh environments following a truststore tutorial.
• Corporate networks where the system store has the needed CA.

When it does NOT apply

• SSL verification errors with truststore already installed, which is a certificate problem, not an import problem.
• Python below 3.10, where truststore cannot work at all.

Why this happens

Python ships its own CA bundle via certifi and ignores the OS store by default, which surprises developers on managed machines. truststore bridges the gap but is a third-party package you must install. The name looks stdlib-official, which is why people assume it is already there.

Compatibility

Python 3.10+. Works with requests, httpx, aiohttp, and urllib3 via the documented integration points.

truststore is a small stdlib-adjacent package that makes Python use the operating system's certificate store instead of certifi's bundle. It is not in the standard library, so import truststore fails until you install it. The project README documents pip install truststore and the truststore.inject_into_ssl() / SSLContext usage. It only works on Python 3.10+, which is the other common gotcha after the missing install.