There are various ways to create fsnative instances:

# create from unicode text
>>> senf.fsnative(u"foo")

# create form some serialized format
>>> senf.bytes2fsn(b"foo", "utf-8")

# create from an URI
>>> senf.uri2fsn("file:///foo")

# create from some Python path-like
>>> senf.path2fsn(b"foo")

You can mix and match the fsnative type with ASCII str on all Python versions and platforms:

>>> senf.fsnative(u"foo") + "bar"
>>> senf.fsnative(u"foo").endswith("foo")
>>> "File: %s" % senf.fsnative(u"foo")
'File: foo'

Now that we have a fsnative, what can we do with it?

>>> path = senf.fsnative(u"/foo")

# We can print it
>>> senf.print_(path)

# We can convert it to text for our favorite GUI toolkit
>>> senf.fsn2text(path)

# We can convert it to an ASCII only URI
>>> senf.fsn2uri(path)

# We can serialize the path so we can save it somewhere
>>> senf.fsn2bytes(path, "utf-8")

The functions in the stdlib usually return the same type as was passed in. If we pass in a fsnative to os.listdir, we get one back as well.

>>> files = os.listdir(senf.fsnative(u"."))
>>> isinstance(files[0], senf.fsnative)

In some cases the stdlib functions don’t take arguments and always return the same type. For those cases Senf provide alternative implementations.

>>> isinstance(senf.getcwd(), senf.fsnative)

A similar problem arises with stdlib collections. Senf provides alternatives for sys.argv and os.environ.

>>> isinstance(senf.argv[0], senf.fsnative)
>>> isinstance(senf.environ["PATH"], senf.fsnative)

Also for os.environ related functions.

>>> isinstance(senf.getenv("HOME"), fsnative)
>>> isinstance(senf.expanduser("~"), fsnative)

If you work with files a lot your unit tests will probably need temporary files. Senf provides wrappers for tempfile functions which always return a fsnative.

>>> senf.mkdtemp()
>>> isinstance(_, senf.fsnative)