Changing the number of iterations in a for loop

Question

I have code like this:

loopcount = 3
for i in range(1, loopcount)
   somestring = \'7\'
   newcount = int(somestring)
   loopcount = newcount

Answer 1

Here is a more complete implementation of the adjustable_range function provided by Joel Cornett.

def adjustable_range(start, stop=None, step=None):
    if not isinstance(start, int):
        raise TypeError('start')
    if stop is None:
        start, stop = 0, start
    elif not isinstance(stop, int):
        raise TypeError('stop')
    direction = stop - start
    positive, negative = direction > 0, direction < 0
    if step is None:
        step = +1 if positive else -1
    else:
        if not isinstance(step, int):
            raise TypeError('step')
        if positive and step < 0 or negative and step > 0:
            raise ValueError('step')
    if direction:
        valid = (lambda a, b: a < b) if positive else (lambda a, b: a > b)
        while valid(start, stop):
            message = yield start
            if message is not None:
                if not isinstance(message, int):
                    raise ValueError('message')
                stop = message
            start += step