PEP 276 Simple Iterator for ints
kseehof at neuralintegrator.com
Thu Nov 15 19:29:44 CET 2001
Hey, what ever happened to the int[:10] iterator idea?
>>> for i in int[2:10:2]: print i,
2 4 6 8
Like PEP 276, it doesn't require new syntax (just implement a slice operator
int[3:8] should return an iterator equivalent to [3,4,5,6,7]
int[-4::2] should return an infinite sequence iterator [-4, -2, 0, 2, ...]
I think that this solves all of the problems that PEP 276 solves, without
any inconsistent idioms or warts.
Here's what http://python.sourceforge.net/peps/pep-0276.html has to
say about it:
- It would be better to reuse the slicing literal syntax attached
to the int class, e.g., int[0:10]
Response: Same as previous response.
""" Response: Shares disadvantages of other proposals that require
changes to the syntax. Needs more design to determine how it
would handle the general case of start,stop,step,
open/closed/half-closed intervals, etc. Needs a PEP."""
In addition, design
consideration needs to be given to what it would mean if one
uses slicing syntax after some arbitrary class other than class
int. Needs a PEP.
What syntax change? There is no syntax change. A slice operator would
simply be added to the int class. Slicing syntax applied to some arbitrary
class would naturally depend on the slice implementation for that class :-)
I agree that it needs a PEP.
Hey, you could also do floats!
>>> for x in float[ :1.0 : 0.2]: print x,
0.0 0.2 0.4 0.6 0.8
[3.0, 2.5, 2.0, 1.5]
Hmm. Complex numbers? Of course the step would be in radians :-) heh heh.
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