Re:What's New in Python 3.11?
by magicalhippo on Monday June 27, 2022 @06:36AM
(#31892675)
> Everything that does not match that expectation is exceptional (to the caller).
No. If you want to read some data from a file if it exists, and continue merrily along if it doesn't, then you cannot simply check if the file exists and then try to open it. That would lead to a race condition. The file could for example be deleted in between the two calls.
The only proper way to handle that is to try to open the file, and if the result of that is FileDoesNotExistError then you continue along merrily.
If the file the caller tries to open is a settings override file, say, then it's not exceptional that the file does not exist.
No. If you want to read some data from a file if it exists, and continue merrily along if it doesn't, then you cannot simply check if the file exists and then try to open it. That would lead to a race condition. The file could for example be deleted in between the two calls.
The only proper way to handle that is to try to open the file, and if the result of that is FileDoesNotExistError then you continue along merrily.
If the file the caller tries to open is a settings override file, say, then it's not exceptional that the file does not exist.