Make an iterator that returns evenly spaced values starting with number start. Often used as an argument to map() to generate consecutive data points. Also, used with zip() to add sequence numbers. Roughly equivalent to:
itertools.count(start=0, step=1)def count(start=0, step=1):
count(10) --> 10 11 12 13 14 ...
count(2.5, 0.5) --> 2.5 3.0 3.5 ...
n = start
while True:
yield n
n += step