to check if the given path is a directory

dirname = '/home/john/python'
os.path.isdir(dirname)

to check if the given path is a file

filename = dirname + 'main.py'
os.path.isfile(filename)

to check if the given path is symbolic link

symlink = dirname + 'some_sym_link'
os.path.islink(symlink)

to check if the given path is a mount point

mount_path = '/home'
os.path.ismount(mount_path)