pros and cons between os.path.exists vs os.path.is

问题:

I'm checking to see if a directory exists, but I noticed I'm using os.path.exists instead of os.path.isdir. Both work just fine, but I'm curious as to what the advantages are for using isdir instead of exists.

回答1:

os.path.exists will also return True if there's a regular file with that name.

os.path.isdir will only return True if that path exists and is a directory, or a symbolic link to a directory.

回答2:

Just like it sounds like: if the path exists, but is a file and not a directory, isdir will return False. Meanwhile, exists will return True in both cases.

回答3:

os.path.isdir() checks if the path exists and is a directory and returns TRUE for the case.

Similarly, os.path.isfile() checks if the path exists and is a file and returns TRUE for the case.

And, os.path.exists() checks if the path exists and doesn’t care if the path points to a file or a directory and returns TRUE in either of the cases.

回答4:

Most of the time, it is the same.

But, path can exist physically whereas path.exists() returns False. This is the case if os.stat() returns False for this file.

If path exists physically, then path.isdir() will always return True. This does not depend on platform.

回答5:

os.path.exists(path) Returns True if path refers to an existing path. An existing path can be regular files (http://en.wikipedia.org/wiki/Unix_file_types#Regular_file), but also special files (e.g. a directory). So in essence this function returns true if the path provided exists in the filesystem in whatever form (notwithstanding a few exceptions such as broken symlinks).

os.path.isdir(path) in turn will only return true when the path points to a directory