【剑指offer】Q32：从1到n整数1出现的次数（python）

def q32(n, len):
if n < 0:
return 0
elif n <= 1:
return n
total = 0
while n > 0:
if  n >= 1 and n < 10:
total += 1
return total
p1 = n % (10**(len - 1))
h = n / (10**(len - 1))
p2 = p1 + 1
n = p1
if h > 1:
total += 10**(len - 1)
else:
total += p2
total += 10 **(len -2) * h * (len - 1)
return total