素数统计

# 判断是否素数
def premi(n):
    if n < 2: return False
    import math
    for i in range(2, math.floor(math.sqrt(n)) + 1):
        if n % i == 0:
            return False
    return True

# 统计素数个数
def premi_count(n):
    premi_list = [True for _ in range(n)]
    count = 0
    for i in range(2, n + 1):
        if premi(i):
            count += 1
            for j in range(i, n, i):
                premi_list[j - 1] = False
    # print(premi_list)
    # print(len(list(filter(premi, range(2, n + 1)))))
    return count


print(premi_count(100))
print(premi(2))