Dive Into Python 3

APPENDIX A ■ PORTING CODE TO PYTHON 3 WITH 2TO3

319

1. maxint becomes maxsize.

2. Any usage of sys.maxint becomes sys.maxsize.

callable() Global Function

In Python 2, you could check whether an object was callable (like a function) with the global callable()

function. In Python 3, this global function has been eliminated. To check whether an object is callable,

check for the existence of the __call__() special method. (See Table A-36.)

Table A-36. The callable() Global Function

Python 2 Python 3

callable(anything) hasattr(anything, '__call__')

zip() Global Function

In Python 2, the global zip() function took any number of sequences and ...