Late to the party, but for anyone tasked with creating their own or wants to see how this would work, here's the function with an added bonus of rearranging the start-stop values based on the desired increment:
def RANGE(start, stop=None, increment=1):
if stop is None:
stop = start
start = 1
value_list = sorted([start, stop])
if increment == 0:
print('Error! Please enter nonzero increment value!')
else:
value_list = sorted([start, stop])
if increment < 0:
start = value_list[1]
stop = value_list[0]
while start >= stop:
worker = start
start += increment
yield worker
else:
start = value_list[0]
stop = value_list[1]
while start < stop:
worker = start
start += increment
yield worker
Negative increment:
for i in RANGE(1, 10, -1):
print(i)
Or, with start-stop reversed:
for i in RANGE(10, 1, -1):
print(i)
Output:
10
9
8
7
6
5
4
3
2
1
Regular increment:
for i in RANGE(1, 10):
print(i)
Output:
1
2
3
4
5
6
7
8
9
Zero increment:
for i in RANGE(1, 10, 0):
print(i)
Output:
'Error! Please enter nonzero increment value!'