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Re: Resetting the Range start in the middle of a loop

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On Fri, 23 Oct 2015 08:42:53 -0700, bigred04bd3 wrote:

> I am wanting to reset a Range start while a loop is running.  here is what
> I have:
> 
> s = 1
> for i in range(s, 1000):
>     # do stuff
>         for r in range(i, 1000):
>             # do stuff
>             s = s + 100  #example
>             break
> 
> 
> I've also tried to update the i as well, but it just continues on to the
> next number as if it was never updated.

You either need a while loop or a custom iterator. E.g.:

class Iterator(object):
    def __init__(self, start, end):
        self.cur = start
        self.end = end

    def set(self, cur):
        self.cur = cur

    def __iter__(self):
        return self

    def next(self):
        if self.cur >= self.end:
            raise StopIteration
        i = self.cur
        self.cur += 1
        return i

So then you can do e.g.:

it = Iterator(s, 1000)
for i in it:
    # do stuff
    for r in range(i, 1000):
        # do stuff
        s = s + 100  #example
        it.set(s)
        break

Unless you need to do this sort of thing a lot, use a while loop.

A "for" loop is used when the set of values is known in advance.
C's "for" loops (since copied by other C-like languages) are "while" loops
in disguise. Python's "for" loops are actually "for" loops.

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Thread

Resetting the Range start in the middle of a loop bigred04bd3@gmail.com - 2015-10-23 08:42 -0700
  Re: Resetting the Range start in the middle of a loop John Gordon <gordon@panix.com> - 2015-10-23 17:15 +0000
  Re: Resetting the Range start in the middle of a loop Peter Pearson <pkpearson@nowhere.invalid> - 2015-10-23 17:23 +0000
  Re: Resetting the Range start in the middle of a loop Steven D'Aprano <steve@pearwood.info> - 2015-10-24 11:05 +1100
  Re: Resetting the Range start in the middle of a loop Nobody <nobody@nowhere.invalid> - 2015-10-24 03:13 +0100
  Re: Resetting the Range start in the middle of a loop bigred04bd3@gmail.com - 2015-10-23 19:31 -0700

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