python · Python
The message
ImportError: cannot import name 'User' from partially initialized module 'models' (most likely due to a circular import)
What it means
Two modules import each other, so you asked for a name from a module that is only half-loaded. It comes from an A imports B, B imports A shape, and it is common right after splitting a file when one type hint pulls an import back the other way. Change from y import Thing to import y and use y.Thing inside the function: the lookup happens later, and the cycle stops mattering.
The fix
There is no one-line command for this. The explanation says what to look at instead.
- 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 “ImportError: cannot import name 'User' from partially initialized module 'models' (most likely due to a circular import)” mean?
Two modules import each other, so you asked for a name from a module that is only half-loaded. It comes from an A imports B, B imports A shape, and it is common right after splitting a file when one type hint pulls an import back the other way. Change from y import Thing to import y and use y.Thing inside the function: the lookup happens later, and the cycle stops mattering.
Q. How do I fix it?
There is no one-line command. The explanation above says what to look at instead.
Q. Which tool prints this?
python. It sits under Python, and the message runs to 17 words.