ModuleNotFoundError: No module named 'lxml'

lxml is not installed in the Python running your code. Run python -m pip install lxml and the import works. On most systems pip fetches a prebuilt wheel, so there is nothing else to do. If pip tries to build from source and fails, you are on a platform without wheels and need the libxml2/libxslt development headers first.

The error

ModuleNotFoundError: No module named 'lxml'

Fix it

1. Install lxml with the running interpreter's pip

python -m pip install lxml

Expected: Successfully installed lxml-....

2. Confirm the import

python -c "from lxml import etree; print(etree.LXML_VERSION)"

Expected: prints a version tuple like (5, 2, 1, 0).

3. If pip starts compiling and fails, add the system libraries (Linux)

sudo apt-get install libxml2-dev libxslt1-dev
python -m pip install lxml

Expected: the build now finds the headers and completes. Only needed where no wheel exists, such as Alpine/musl or unusual architectures.

When this applies

• import lxml, from lxml import etree, or from lxml import html raises ModuleNotFoundError
• a scraper dependency (pyquery, newspaper3k, ebook tooling) fails importing lxml
• a fresh venv, container, or CI runner

When it does NOT apply

• ImportError: DLL load failed on Windows is a bitness mismatch, not a missing package
• No module named 'lxml_html_clean' is the lxml 5.x split, install that package
• cannot import name 'etree' from 'lxml' means lxml imported but is broken or ancient

Compatibility

lxml 4.x and 5.x. Wheels cover CPython 3.8+ on Windows, macOS (Intel and ARM), and manylinux. Python 3.12+ needs lxml 4.9.3 or newer.

Why it happens

lxml is a C extension, so unlike pure-Python packages it cannot be vendored by accident; if it was never installed, the import fails outright. Scraping libraries treat it as an optional-but-assumed dependency, so the error often surfaces one layer up (in pyquery or BeautifulSoup with the lxml parser) instead of at your own import line.

Edge cases

• Do not pip install xml. There is no such package that provides lxml.
• If you are on Python 3.12+ with an old pinned lxml (4.9.2 or older), upgrade: old lxml wheels do not support 3.12 and old source builds fail.
• Corporate proxies sometimes block the wheel download and pip silently falls back to a source build that fails. pip install --only-binary lxml lxml forces the wheel or errors clearly.