What's the difference between io.open() and os.open() on Python?

Question

I realised that the open() function I've been using was an alias to io.open() and that importing * from os would overshadow that.

What's the difference between opening files through the io module and os module?

Answer 1

io.open() is the preferred, higher-level interface to file I/O. It wraps the OS-level file descriptor in an object that you can use to access the file in a Pythonic manner.

os.open() is just a wrapper for the lower-level POSIX syscall. It takes less symbolic (and more POSIX-y) arguments, and returns the file descriptor (a number) that represents the opened file. It does not return a file object; the returned value will not have read() or write() methods.

From the os.open() documentation:

This function is intended for low-level I/O. For normal usage, use the built-in function open(), which returns a “file object” with read() and write() methods (and many more).

Answer 2

Absolutely everything:

• os.open() takes a filename as a string, the file mode as a bitwise mask of attributes, and an optional argument that describes the file permission bits, and returns a file descriptor as an integer.

• io.open() takes a filename as a string or a file descriptor as an integer, the file mode as a string, and optional arguments that describe the file encoding, buffering used, how encoding errors and newlines are handled, and if the underlying FD is closed when the file is closed, and returns some descendant of io.IOBase.