OS modules in python

os.path.splitext() 

This method in Python is used to split the path name into a pair root and ext. Here, ext stands for extension and has the extension portion of the specified path while root is everything except ext part.
ext is empty if specified path does not have any extension. If the specified path has leading period (‘.’), it will be ignored.

  path name                          root                        ext
/home/User/Desktop/file.txt    /home/User/Desktop/file              .txt
/home/User/Desktop             /home/User/Desktop                  {empty}
file.py                               file                          .py
.txt                                  .txt                         {empty}   

os.name

The name of the operating system dependent module imported. The following names have currently been registered: 'posix', 'nt', 'java'.

os.chdir(path)

os.mkdir(path, mode=0o777, *, dir_fd=None)

Create a directory named path with numeric mode mode.

If the directory already exists, FileExistsError is raised.

os.makedirs(name, mode=0o777, exist_ok=False)

Recursive directory creation function. Like mkdir(), but makes all intermediate-level directories needed to contain the leaf directory.

If exist_ok is False (the default), an FileExistsError is raised if the target directory already exists.

os.remove(path, *, dir_fd=None)

Remove (delete) the file path. If path is a directory, an IsADirectoryError is raised. Use rmdir() to remove directories.

This function can support paths relative to directory descriptors.

On Windows, attempting to remove a file that is in use causes an exception to be raised; on Unix, the directory entry is removed but the storage allocated to the file is not made available until the original file is no longer in use.

os.removedirs(name)

Remove directories recursively. Works like rmdir() except that, if the leaf directory is successfully removed, removedirs() tries to successively remove every parent directory mentioned in path until an error is raised (which is ignored, because it generally means that a parent directory is not empty). For example, os.removedirs('foo/bar/baz') will first remove the directory 'foo/bar/baz', and then remove 'foo/bar' and 'foo' if they are empty. Raises OSError if the leaf directory could not be successfully removed.

os.rename(src, dst, *, src_dir_fd=None, dst_dir_fd=None)

Rename the file or directory src to dst. If dst exists, the operation will fail with an OSError subclass in a number of cases:

On Windows, if dst exists a FileExistsError is always raised.

os.rmdir(path, *, dir_fd=None)

Remove (delete) the directory path. If the directory does not exist or is not empty, an FileNotFoundError or an OSError is raised respectively. In order to remove whole directory trees, shutil.rmtree() can be used.

This function can support paths relative to directory descriptors.

os.path.abspath(path)

Return a normalized absolutized version of the pathname path. On most platforms, this is equivalent to calling the function normpath() as follows: normpath(join(os.getcwd(), path)).

os.path.dirname(path)

Return the directory name of pathname path. This is the first element of the pair returned by passing path to the function split().

os.path.isfile(path)

Return True if path is an existing regular file. This follows symbolic links, so both islink() and isfile() can be true for the same path.

Changed in version 3.6: Accepts a path-like object.

os.path.isdir(path)

Return True if path is an existing directory. This follows symbolic links, so both islink() and isdir() can be true for the same path.

Changed in version 3.6: Accepts a path-like object.

os.path.join(path, *paths)

Join one or more path components intelligently. The return value is the concatenation of path and any members of *paths with exactly one directory separator (os.sep) following each non-empty part except the last, meaning that the result will only end in a separator if the last part is empty. If a component is an absolute path, all previous components are thrown away and joining continues from the absolute path component.

On Windows, the drive letter is not reset when an absolute path component (e.g., r'\foo') is encountered. If a component contains a drive letter, all previous components are thrown away and the drive letter is reset. Note that since there is a current directory for each drive, os.path.join("c:", "foo") represents a path relative to the current directory on drive C: (c:foo), not c:\foo.

Changed in version 3.6: Accepts a path-like object for path and paths.

os.path.split(path)

Split the pathname path into a pair, (head, tail) where tail is the last pathname component and head is everything leading up to that. The tail part will never contain a slash; if path ends in a slash, tail will be empty. If there is no slash in path, head will be empty. If path is empty, both head and tail are empty. Trailing slashes are stripped from head unless it is the root (one or more slashes only). In all cases, join(head, tail) returns a path to the same location as path (but the strings may differ). Also see the functions dirname() and basename().

Changed in version 3.6: Accepts a path-like object.

Source :
https://www.geeksforgeeks.org/python-os-path-splitext-method/
https://docs.python.org/3/library/os.html