题解 | 挑7
import re
def search_7(n):
sum = 0
for i in range(1,n+1):
if i%7==0:
sum += 1
continue
elif re.search(r'7',str(i)):#正则表达式表示函数7的数
sum += 1
return sum
n = int(input())
print(search_7(n))
