2018-10-10-day9Homework

10.10 函数基础作业

1. 编写一个函数，求1+2+3+...+N

 def my_sum(n):  
     sum1 = 0
     for x in range(1,n+1):
         sum1 += x
     return sum1
 print(my_sum(5))

结果：15

2. 编写一个函数，求多个数中的最大值

 def my_max(*num):
     max = 0
     for x in num:
         if x >max:
             max = x
     return max
 print(my_max(5,64,67,13,84,64,90,31,47))

结果：90

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 tou_zi(n):
     import random
     i = 0
     sum1 = 0
     while i < n:
         x = random.randint(1,6)
         sum1 += x
         i += 1
     return sum1
 print(tou_zi(2))

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_keyvalue(dict1):
    dict2={}
    for index1 in dict1:
        value = index1
        key = dict1[index1]
        dict2.setdefault(key,value)
    return dict2
print(change_keyvalue({'name':'hqf','sex':'man','age':18}))

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_alp(n):
     new_str = ''
     for x in n:
         if x.isalpha():
             new_str += x
     return new_str
 print(get_alp('d4sa564das6'))

结果：dasdas

6. 写一个函数，求多个数的平均值

 def my_avrage(*n):
     sum = 0
     num = 0
     avr = float(0)
     for x in n:
         sum += x
         num +=1
     avr = sum/num
     return avr
 print(my_avrage(5,654,2,78,312,4))

结果：175.83

7. 写一个函数，默认求10的阶层，也可以求其他数的阶层

 def my_jiecheng(n=10):
     jiecheng = 1
     for x in range(1,n+1):
         jiecheng *= x
     return jiecheng
 print(my_jiecheng())

结果：3628800

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_suanfa(list1):
     num1 = 0
     if list1[0] == '+':
         del list1[0]
         answer = list1[0]
         for index in range(0,len(list1)):
             num1 = list1[index]
             answer += num1
     elif list1[0] == '-':
         del list1[0]
         answer = list1[0]
         for index in range(0,len(list1)):
             num1 = list1[index]
             answer -= num1
     else:
         del list1[0]
         answer = list1[0]
         for index in range(0, len(list1)):
             num1 = list1[index]
             answer *= num1
     return answer
 print(my_suanfa(['+',1,2,3,4,5]))
 print(my_suanfa(['-',1,2,3,4,5]))
 print(my_suanfa(['*',1,2,3,4,5]))

结果：16，-14，120
9.写一个函数，求指定列表中，指定的元素的个数

 def my_count(list1,str1):
     count1 = 0
     for x in list1:
         if x == str1:
             count1 += 1
     return count1
 print(my_count([1,2,3,4,1,2,3,1,2,1],3))

结果：2
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)

 def my_index(list1,str1):
     num =''
     for index1 in range(0,len(list1)):
         if list1[index1] == str1:
             num += 'index1'
             print(index1)
 my_index([1, 1, 2, 3, 4, 4, 3, 2, ], 2)

结果：2、7