Programming languages generally have limits—explicit or implicit—on various
aspects of their operation. Things like the maximum length of an
identifier or the range of values that a variable can store are fairly
obvious examples, but there are others, many of which are unspecified
by the language designers and come about from various implementations of
the language. That ambiguity has consequences, so nailing down a wide
variety of limits in Python is the target of an ongoing discussion on the
python-dev mailing list.

Source: LWN.net – [$] One million ought to be enough for anybody