python · Python
The message
ModuleNotFoundError: No module named 'requests'
What it means
Python searched every directory on sys.path and found no module with that name. Either it was never installed, or it was installed for a different interpreter — pip install outside a virtual environment and then running inside one produces exactly this. Writing it as python -m pip install installs into the interpreter you are actually running, which removes the mismatch.
The fix
python -m pip install requests- Printed by
- python
- Python
- 18
A Python traceback splits the answer in two — the last line says what went wrong, the frames above it say where — so reading only the last line gives you the name and loses the place, and for the value-is-missing errors such as NoneType and KeyError the cause almost always sits in a frame above the one that crashed.
Reading an error message
- Read from the first line down. The lower you go the more it is about the tool’s internals; the cause is usually at the top.
- If there is a file and a line number, start there — not the top stack frame, but the topmost line that names a file you wrote.
- Search the message verbatim, but strip your own paths and variable names first; those are what stop the search from matching.
- The same condition is worded differently across tool versions. If results look wrong, add the version number to the query.
- Before pasting a fix, check what it throws away. Some of these cannot be undone.
Common questions
Q. What does “ModuleNotFoundError: No module named 'requests'” mean?
Python searched every directory on sys.path and found no module with that name. Either it was never installed, or it was installed for a different interpreter — pip install outside a virtual environment and then running inside one produces exactly this. Writing it as python -m pip install installs into the interpreter you are actually running, which removes the mismatch.
Q. How do I fix it?
python -m pip install requests — before running it, check the explanation above for what this command discards.
Q. Which tool prints this?
python. It sits under Python, and the message runs to 5 words.