The generic abspath implementation could be moved into the genericpath module, where it will be common to both posixpath and ntpath: def abspath(path): """Return an absolute path.""" path = os.fspath(path) if not isabs(path): if isinstance(path, bytes): cwd = os.getcwdb() else: cwd = os.getcwd() path = join(cwd, path) return normpath(path) Then replace it in ntpath if nt._getfullpathname is defined, but with a fallback to the generic implementation if OSError is raised (e.g. for " "): try: from nt import _getfullpathname except ImportError: pass else: def abspath(path): """Return an absolute path.""" try: return _getfullpathname(path) except OSError: return genericpath.abspath(path) This _getfullpathname version also skips the redundant fspath and normpath calls.