What are the default slice indices in Python *really*?

Question

From the python documentation docs.python.org/tutorial/introduction.html#strings:

Slice indices have useful defaults; an omitted first index defaults

Answer 1

Useful to know if you are implementing __getslice__: j defaults to sys.maxsize (https://docs.python.org/2/reference/datamodel.html#object.getslice)

>>> class x(str):
...   def __getslice__(self, i, j):
...     print i
...     print j
...
...   def __getitem__(self, key):
...     print repr(key)
...
>>> x()[:]
0
9223372036854775807
>>> x()[::]
slice(None, None, None)
>>> x()[::1]
slice(None, None, 1)
>>> x()[:1:]
slice(None, 1, None)
>>> import sys
>>> sys.maxsize
9223372036854775807L