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.. _int-object:
int
---
Python 3's ``int`` type is very similar to Python 2's ``long``, except
for the representation (which omits the ``L`` suffix in Python 2). Python
2's usual (short) integers have been removed from Python 3, as has the
``long`` builtin name.
Python 3::
>>> 2**64
18446744073709551616
Python 2::
>>> 2**64
18446744073709551616L
``future`` includes a backport of Python 3's ``int`` that
is a subclass of Python 2's ``long`` with the same representation
behaviour as Python 3's ``int``. To ensure an integer is long compatibly with
both Py3 and Py2, cast it like this::
>>> from builtins import int
>>> must_be_a_long_integer = int(1234)
The backported ``int`` object helps with writing doctests and simplifies code
that deals with ``long`` and ``int`` as special cases on Py2. An example is the
following code from ``xlwt-future`` (called by the ``xlwt.antlr.BitSet`` class)
for writing out Excel ``.xls`` spreadsheets. With ``future``, the code is::
from builtins import int
def longify(data):
"""
Turns data (an int or long, or a list of ints or longs) into a
list of longs.
"""
if not data:
return [int(0)]
if not isinstance(data, list):
return [int(data)]
return list(map(int, data))
Without ``future`` (or with ``future`` < 0.7), this might be::
def longify(data):
"""
Turns data (an int or long, or a list of ints or longs) into a
list of longs.
"""
if not data:
if PY3:
return [0]
else:
return [long(0)]
if not isinstance(data,list):
if PY3:
return [int(data)]
else:
return [long(data)]
if PY3:
return list(map(int, data)) # same as returning data, but with up-front typechecking
else:
return list(map(long, data))
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