How to troubleshoot an "AttributeError: __exit__" in multiproccesing in Python?
The problem is in this line:
with pattern.findall(row) as f:You are using the with statement. It requires an object with __enter__ and __exit__ methods. But pattern.findall returns a list, with tries to store the __exit__ method, but it can't find it, and raises an error. Just use
f = pattern.findall(row)instead.
It is not the asker's problem in this instance but the first troubleshooting step for a generic "AttributeError: __exit__" should be making sure the brackets are there, e.g.
with SomeContextManager() as foo: #works because a new object is referenced...not
with SomeContextManager as foo: #AttributeError because the class is referencedCatches me out from time to time and I end up here -__-
The error also happens when trying to use the
with multiprocessing.Pool() as pool: # ...with a Python version that is too old (like Python 2.X) and does not support using with together with multiprocessing pools.
(See this answer https://stackoverflow.com/a/25968716/1426569 to another question for more details)