day8-作业

1. 编写⼀个函数，求1+2+3+...+N

def my_sum(n):
    sum1 = 0
    for i in range(0, n + 1):
        sum1 += i
    return sum1


print(my_sum(100))

2. 编写⼀个函数，求多个数中的最⼤值

def my_max(list1=[]):
    max1 = max(list1)
    return max1


print(my_max(list1=[1, 2, 3, 4, 88, 99, 10]))

3. 编写⼀个函数，实现摇⾊⼦的功能，打印n个⾊⼦的点数和

import random
def my_sum1(n):
    rand = 0
    for i in range(n):
       rand += random.randint(1, 7)
    return rand

print(my_sum1(5))

4. 编写⼀个函数，交换指定字典的key和value。
   例如:{'a':1, 'b':2, 'c':3} ---> {1:'a', 2:'b', 3:'c'}

def exchange(dict = {}):
    dict2 = {}
    for key in dict:
        dict2.update({dict[key]: key})
    return dict2

print(exchange(dict = {'a':1, 'b':2, 'c':3}))

5. 编写⼀个函数，三个数中的最⼤值

def my_max(list):
    return max(list)


print(my_max([1, 2, 3]))

6. 编写⼀个函数，提取指定字符串中的所有的字⺟，然后拼接在⼀起后打印出来
   例如：'12a&bc12d--' ---> 打印'abcd'

def alpha(str1):
    str2 = ''
    for i in range(len(str1)):
        if ('a' <= str1[i] <= 'z') or ('A' <= str1[i] <= 'Z'):
            print((str2 + str1[i]), end="")

alpha('dsfds445sdf')

7. 写⼀个函数，求多个数的平均值

def ave(list):
    sum = 0
    for i in list:
        sum += i
    return sum / len(list)

print(ave([1,2,3,4,5,6,7,8,9,0]))

8. 写⼀个函数，默认求10的阶层，也可以求其他数的阶层

def factorial(n=10):
    sum = 1
    for i in range(1, n + 1):
        sum *= i
    return sum

print(factorial())

9. 写⼀个函数，可以对多个数进⾏不同的运算
   例如: operation('+', 1, 2, 3) ---> 求 1+2+3的结果
   operation('-', 10, 9) ---> 求 10-9的结果
   operation('', 2, 4, 8, 10) ---> 求 24810的结构

def more_operation(str, list=[]):
    sum1 = 0
    sum2 = 0
    sum3 = 1
    if str == '+':
        for i in list:
            sum1 += i
        return sum1
    elif str == '-':
        for i in list:
            sum2 -= i
        return sum2 + list[0] * 2
    elif str == '*':
        for i in list:
            sum3 *= i
        return sum3
    elif str == '/':
        for i in list:
            sum3 /= i
        return sum3 * (list[0] ** 2)


list1 = [10, 20, 30, 50]
print(more_operation('/', list1))