python · Python
The message
RecursionError: maximum recursion depth exceeded
What it means
A function called itself deeper than the default limit of 1000 frames. Far more often than a genuinely deep computation, this means the stopping condition is missing or never reached; indirect recursion counts too, such as a __getattr__ or a property that reads its own attribute again. Find the two or three frames that repeat in the traceback and fix the base case first. sys.setrecursionlimit() does raise the ceiling, but it lets you overrun the real C stack, and then Python dies outright instead of raising — rewriting the recursion as a loop is the safe answer.
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 “RecursionError: maximum recursion depth exceeded” mean?
A function called itself deeper than the default limit of 1000 frames. Far more often than a genuinely deep computation, this means the stopping condition is missing or never reached; indirect recursion counts too, such as a __getattr__ or a property that reads its own attribute again. Find the two or three frames that repeat in the traceback and fix the base case first. sys.setrecursionlimit() does raise the ceiling, but it lets you overrun the real C stack, and then Python dies outright instead of raising — rewriting the recursion as a loop is the safe answer.
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 5 words.