exp.py

def my_generator(maximum):
    n = 0
    while n < maximum:
        n += 1
        yield n
    return 'Done'


g = my_generator(maximum=5)

next(g)
# 1
next(g)
# 2
next(g)
# 3
next(g)
# 4
next(g)
# 5
next(g)
# Traceback (most recent call last):
#   File "/usr/lib/python3.6/code.py", line 91, in runcode
#     exec(code, self.locals)
#   File "<input>", line 1, in <module>
# StopIteration: Done