1. 编写一个函数，求1+2+3+...+N

def my_sum(n1):
    sum1 = 0
    for i in range(1,n1+1):
        sum1 += i
    return sum1

k = my_sum(5)
print(k,"\n~~~~~~~~~~~~~~~~~~~~~")

2. 编写一个函数，求多个数中的最大值

 def my_max(*n2):
            num_max = 0
            for i in n2:
                if num_max < i:
                    num_max = i
            return num_max
    
        j = my_max(12,3,44)
        print(j,"\n~~~~~~~~~~~~~~~~~~~~~")

3. 编写一个函数，实现摇骰子的功能，打印n个骰子的点数和

    def sum_of_touzi(n):
        sum2 = 0
        for i in range(0,n):
            x = random.randint(1, 6)
            print(x)
            sum2 += x
        return sum2
    
    l = sum_of_touzi(4)
    print(l,'\n~~~~~~~~~~~~~~~~~~~~~~~~~~')

4. 编写一个函数，交换指定字典的key和value。

如:{'a':1, 'b':2, 'c':3} ---> {1:'a', 2:'b', 3:'c'}

    def change_key_value(n):
        list1 = []
        dict1 = {}
        list1 = n.items()
        for t in list1:
            x,y = t
            x,y = y,x
            dict1[x] = y
    
        return dict1
    
    m = change_key_value({'a':5, 'b':8, 'c':9})
    print(m,'\n~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~')

5. 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

如:'12a&bc12d--' ---> 打印'abcd'

    def get_letter(n):
        str1 =''
        for letter1 in n:
            if 'a'<= letter1 <= 'z'or 'A' <= letter1 <='Z':
                str1 += letter1
    
        print(str1)
    
    get_letter("123nl1kjn3123jn1l")
    print('~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~')

6. 写一个函数，求多个数的平均值

    def my_average(*n):
        sum = 0
        for i in n:
            sum += i
        average1 = sum/len(n)
        return average1
    
    a = my_average(1,2,3,7,8,9)
    print(a,"\n~~~~~~~~~~~~~~~~~~~~~~~~~~~~")

7. 写一个函数，默认求10的阶层，也可以求其他数的阶层

    def jiecheng(n = 10):
        num = 1
        for i in range(1,n+1):
            num *= i
    
        return num
    
    b = jiecheng()
    c = jiecheng(5)
    print(b,c,'\n~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~')

8. 写一个函数，可以对多个数进行不同的运算

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 my_math(*n):
    
            if n[0] == '+':
                num = n[1]
                for i in range(2, len(n)):
                    num += n[i]
            if n[0] =='-':
                num = n[1]
                for i in range(2, len(n)):
                    num -= n[i]
            if n[0] =='*':
                num = n[1]
                for i in range(2, len(n)):
                    num *= n[i]
            if n[0] == '/':
                num = n[1]
                for i in range(2, len(n)):
                    num /= n[i]
            return num
    
    d = my_math('+',1,2,3,4,5)
    e = my_math('-',10,6,7)
    f = my_math('*',4,5,6)
    p = my_math('/',9,6)
    print(d)
    print(e)
    print(f)
    print(p)

9.写一个函数，求指定列表中，指定的元素的个数

m为指定列表，n为指定元素

    def my_func(m,n):
        i = 0
        for x in m:
            if x == n:
                i += 1
    
        return i
    
    q = my_func([1,2,3,4,5,1,3,4,5,3,45],3)
    print(q)

10.写一个函数，获取指定列表中指定元素对应的下标(如果有多个，一起返回)

m为指定列表，n为指定元素

    def get_xiabiao(m, n):
list = []
for i in range(len(m)):
    if m[i] == n:
        list.append(i)

return list


r = get_xiabiao([1, 2, 3, 4, 5, 1, 3, 4, 5, 3, 45], 3)
print(r)