Python Generating Infinite Loop When First Arg is 0 -

i not understanding why below code falling infinite loop when 'start' argument of totalarea 0. have been watching code run in python tutor, , j executes through value of stop -1, resets 0 without moving onto value of stop.

import math def totalarea(start, stop, step):     def f(x):         return 10*math.e**(math.log(0.5)/5.27 * x)      area = 0.0     j = start      while j <= len(range(start, stop)):          j in range(start, stop):             area += float(step) * f(j)      print area  totalarea(0, 11, 1) 

while j <= len(range(start, stop)):     j in range(start, stop): 

every time loop ends, j = 10

len(range(start, stop)) 11

so j <= len(range(start, stop)) forever

the while loop seems entirely superfluous. try removing entirely:

def totalarea(start, stop, step):     def f(x):         return 10*math.e**(math.log(0.5)/5.27 * x)      area = 0.0     j = start      j in range(start, stop):         area += float(step) * f(j)      print area