How to Fix "ModuleNotFoundError: No Module Named" in virtualenv / venv
You install a package with pip and it appears to succeed, but your script still can't find it. This almost always means the package was installed into a...
Category
Python
Tracking down Python errors, packaging and environment problems.
How to Resolve "pip install Error: legacy-install-failure"
Installing a package fails with a generic "legacy-install-failure" summary, which is pip's way of saying a package's older-style build process crashed — but...
How to Fix "TypeError: 'Required' Object Is Not Subscriptable" in Python
Your code raises a subscriptable error pointing at something named Required, a name you probably never typed yourself. This specific error is a strong signal...
How to Resolve "RecursionError: Maximum Recursion Depth Exceeded" in Python
A recursive function that should eventually finish instead crashes after making far more calls than expected. Python enforces a default recursion depth limit...
How to Fix "AttributeError: 'NoneType' Object Has No Attribute" Error
Your code calls a method or accesses a property on a variable that turns out to be None instead of the object you expected. This is one of the most common...
How to Resolve "Python SSL: CERTIFICATE_VERIFY_FAILED" With urllib or requests
An HTTPS request from Python fails with a certificate verification error, even though the same URL loads fine in a browser. This is Python's SSL layer refusing...
How to Fix "SyntaxError: Non-Default Argument Follows Default Argument"
Defining a function fails before it can even run, with Python's parser rejecting the parameter order outright. Unlike most runtime errors, this one is caught...
How to Resolve "UnicodeDecodeError: 'utf-8' Codec Can't Decode Byte"
Opening or reading a file crashes with Python complaining it can't decode a specific byte as UTF-8. This means the file isn't actually UTF-8 encoded — it's...
How to Fix "MemoryError" When Processing Large Files in pandas/Python
Loading a large CSV or dataset into pandas crashes the process instead of completing, because the entire file is being loaded into RAM at once and there simply...