python函数练习题若干

#!/usr/bin/env python3
# -*- encoding: utf-8 -*-


def line():
    '''练习1，写一个打印一条横线的函数'''
    print("-" * 30)
    
line()


def line_2(i):
    '''练习2，输入参数，打印出自定义行数的横线'''
    for num in range(i):
        print(f"第{num+1}行 " + "-" * 30)
    return
    
i = eval(input("请输入自定义横线的行数："))
line_2(i)


def sum(a, b, c):
    '''练习3，函数求三个数的和'''
    sum = a + b + c
    return sum

num = sum(10, 20, 30)
print(f"sum : {num}")


def avg(a, b, c):
    '''练习3，函数求三个数的平均值'''
    avg = a / 2 + b / 2 + c / 2
    return avg
    
num_2 = avg(10, 20, 81)
print(f"avg : {num_2}")