1.編寫一個(gè)函數(shù)亡电，求1+2+3+···+N

def my_sum(N):
    my_list = []
    for num in range(N):
        my_list.append(num+1)
    return sum(my_list)

print('1+2+3+···+N的和為：%d' % (my_sum(6)))

2.編寫一個(gè)函數(shù)，求多個(gè)數(shù)中的最大值

def my_max(*num):
    return max(*num)

print('最大值為：%d' % my_max(12,13,14,15,2,21,99,87))
print('最大值為：%d' % my_max(1,2,3,4,5))

3.編寫一個(gè)函數(shù)锁保，實(shí)現(xiàn)搖色子的功能除抛，打印n個(gè)色子的點(diǎn)數(shù)和

import random
def my_dice(N):
    sum = 0
    for _ in range(N):
        num = random.randint(1,6)
        print('每次色子的點(diǎn)數(shù)：%d' % (num))
        sum += num
    return sum
print('n次色子的點(diǎn)數(shù)和：%d' % (my_dice(5)))

4.編寫一個(gè)函數(shù)狮杨，交換指定字典的key和value

def my_exchange(dict_exchange:dict):
    for key in dict_exchange:
        key_exchange = key
        value = dict_exchange[key]
        del dict_exchange[key]  # 為什么不能直接添加鍵值對(duì)，
        # 報(bào)錯(cuò)RuntimeError: dictionary changed size during iteration到忽，說(shuō)：字典在迭代過(guò)程中改變了大小
        dict_exchange[value] = key_exchange
    return dict_exchange

print(my_exchange({'a':1, 'b':2, 'c':3,'d':4}))  # 成功橄教，但是加了'd':4就失敗
print(my_exchange({'Q':'q', 'W':'w', 'E':'e', 'R':'r'})) # 對(duì)換失敗，遍歷key時(shí)喘漏，新的key又被遍歷
# 因?yàn)樵值湓诒闅v過(guò)程中被改變了鍵值對(duì)护蝶，所以會(huì)遍歷失敗，和remove一個(gè)道理陷遮，因此滓走，創(chuàng)建一個(gè)新字典垦江，添加新的鍵值對(duì)
def my_exchange(dict_exchange:dict):
    new_dict_exchange = {}
    for key in dict_exchange:
        key_exchange = key
        value = dict_exchange[key]
        # del dict_exchange[key]  # 為什么不能直接添加鍵值對(duì)帽馋，報(bào)錯(cuò)RuntimeError: dictionary changed size during iteration
        new_dict_exchange[value] = key_exchange
    return new_dict_exchange

print(my_exchange({'a':1, 'b':2, 'c':3,'d':4}))
print(my_exchange({'Q':'q', 'W':'w', 'E':'e', 'R':'r'}))

5.編寫一個(gè)函數(shù)，求三個(gè)數(shù)中的最大值

def my_max(a, b, c):
    return max(a, b, c)

print(my_max(99, 123, 19))

6.編寫一個(gè)函數(shù)比吭，提取指定字符串中的所有的字母绽族，然后拼接在一起后打印出來(lái)

def my_str(str1:str):
    list1 = []
    for item in str1:
        if 'a' <= item <='z' or 'A' <= item <='Z':
            list1.append(item)
    return ''.join(list1)  #  return 前面的縮進(jìn)很重要，放在不同的位置衩藤，返回值不同

print(my_str('231ji2ds12aj12'))

7.編寫一個(gè)函數(shù)吧慢，求多個(gè)數(shù)的平均值

def my_average(*num):  #  num = (1,2,3,4,5) 是個(gè)元組
    return sum(num)/len(num)
print(my_average(10, 2, 30, 4, 50))

8.編寫一個(gè)程序，默認(rèn)求10的階乘赏表，也可以求其他數(shù)的階乘

def my_factorial(num=10):
    sum = 1
    for item in range(1,num+1):
        sum *= item
    return sum
print(my_factorial())

9.編寫一個(gè)程序检诗，可以對(duì)多個(gè)數(shù)進(jìn)行不同的運(yùn)算

def my_operation(way,*num):
    if str(way) == '+':
        return sum(num)
    elif str(way) == '-':
        return num[0] - num[1]
    elif str(way) == '*':
        number = 1
        for item in num:
            number *= item
        return number

print(my_operation('+', 100, 200, 300))
print(my_operation('-', 100, 39))
print(my_operation('*', 5, 4, 3, 2, 1))