PYTHON

range

print(range(1, 4))    # [1, 2, 3] 1 through 4, excluding 4
print(range(1, 10, 2)) # [1, 3, 5, 7, 9] 1 through 10, counting by 2s, excluding 10

range

#range function
for a in range(5,-9,-1):#note step can not be 0 or else it will generate error.
    print(a,end=',')
output:
5,4,3,2,1,0,-1,-2,-3,-4,-5,-6,-7,-8,