Do functions in the "os" module wait to be finished?

Question

With:

import os
for file in files:
   os.remove(file)

Will it wait for every file to be removed like a synchronous function in each call to os.remove(), or will it iterate through while calling os.remove()?

Answer 1

Generally, the os module provides wrappers around system calls of the operating system. For example, on Linux the os.remove/os.unlink functions correspond to the unlink system call. These functions wait until the system call has finished.

Whether this means that the high level operation intended by the program has finished depends on the use-case.
For example, unlink merely removes the path pointing to the file content; if there are other paths for the same file (i.e. hardlinks) or processes with a file handle on it, the file content remains. Only when all references are gone is the file content eligible for removal from the filesystem (similar to reference counting). The filesystem itself may arbitrarily delay removal of the content, and distributed filesystems may have additional consistency and synchronisation constraints.

As a rule of thumb, if there are no special requirements then it is fine to consider the os call to be prompt and synchronous. If there are specific requirements, such as file content being completely destroyed, read up on the specific behaviour of the involved components.