• 叠加多个装饰器、yield表达式、三元表达式、生成式、函数的递归 练习


    # 1、文件内容如下,标题为:姓名,性别,年纪,薪资
    # egon male 18 3000
    # alex male 38 30000
    # wupeiqi female 28 20000
    # yuanhao female 28 10000

    # 要求:
    # 从文件中取出每一条记录放入列表中,
    # 列表的每个元素都是{'name':'egon','sex':'male','age':18,'salary':3000}的形式
    '''
    keys=['name','sex','age','salary']
    l=[]
    dic={}.fromkeys(keys,None)
    dic1={}.fromkeys(keys,None)
    dic2={}.fromkeys(keys,None)
    dic3={}.fromkeys(keys,None)
    def info():
    with open('db.txt',mode='rt',encoding='utf-8')as f:
    f.__iter__()
    line=f.__next__()
    dic['name'], dic['sex'], dic['age'], dic['salary'] = line.strip().split(' ')
    l.append(dic)
    line1 = f.__next__()
    dic1['name'], dic1['sex'], dic1['age'], dic1['salary'] = line1.strip().split(' ')
    l.append(dic1)
    line2 = f.__next__()
    dic2['name'], dic2['sex'], dic2['age'], dic2['salary'] = line2.strip().split(' ')
    l.append(dic2)
    line3 = f.__next__()
    dic3['name'], dic3['sex'], dic3['age'], dic3['salary'] = line3.strip().split(' ')
    l.append(dic3)

    info()

    print(l)
    '''
    # 2 根据1得到的列表,取出所有人的薪资之和
    '''
    l=[
    {'name': 'egon', 'sex': 'male', 'age': '18', 'salary': '3000'},
    {'name': 'alex', 'sex': 'male', 'age': '38', 'salary': '30000'},
    {'name': 'wupeiqi', 'sex': 'female', 'age': '28', 'salary': '20000'},
    {'name': 'yuanhao', 'sex': 'female', 'age': '28', 'salary': '10000'}
    ]
    sum=0
    for i in l:
    salary=i['salary']
    salary=int(salary)
    sum += salary
    print(sum)
    '''
    # 3 根据1得到的列表,取出所有的男人的名字
    '''
    l=[
    {'name': 'egon', 'sex': 'male', 'age': '18', 'salary': '3000'},
    {'name': 'alex', 'sex': 'male', 'age': '38', 'salary': '30000'},
    {'name': 'wupeiqi', 'sex': 'female', 'age': '28', 'salary': '20000'},
    {'name': 'yuanhao', 'sex': 'female', 'age': '28', 'salary': '10000'}
    ]
    new_l=[]
    for i in l:
    name=i['name']
    new_l.append(name)
    print(new_l)
    '''
    # 4 根据1得到的列表,将每个人的信息中的名字映射成首字母大写的形式
    '''
    l=[
    {'name': 'egon', 'sex': 'male', 'age': '18', 'salary': '3000'},
    {'name': 'alex', 'sex': 'male', 'age': '38', 'salary': '30000'},
    {'name': 'wupeiqi', 'sex': 'female', 'age': '28', 'salary': '20000'},
    {'name': 'yuanhao', 'sex': 'female', 'age': '28', 'salary': '10000'}
    ]
    for i in l:
    old=i['name'][0]
    new=i['name'][0].upper()
    new_l=i['name'].replace(old,new)
    print(new_l)
    old_l=i['name']
    print(old_l)
    i['name']=new_l
    print(l)
    '''
    # 5 根据1得到的列表,过滤掉名字以a开头的人的信息
    '''
    l=[
    {'name': 'egon', 'sex': 'male', 'age': '18', 'salary': '3000'},
    {'name': 'alex', 'sex': 'male', 'age': '38', 'salary': '30000'},
    {'name': 'wupeiqi', 'sex': 'female', 'age': '28', 'salary': '20000'},
    {'name': 'yuanhao', 'sex': 'female', 'age': '28', 'salary': '10000'}
    ]
    new_l=[]
    for i in l:
    name=i['name']
    print(name)
    if name.startswith('a'):
    print(name)
    else:
    new_l.append(i)
    print(new_l)
    '''
    # 6 使用递归打印斐波那契数列(前两个数的和得到第三个数,如:0 1 1 2 3 4 7...)
    '''
    def f(n):
    if n == 1:
    return 0
    elif n == 2:
    return 1
    elif n == 3:
    return 1
    else:
    return f(n - 1) + f(n - 2)
    for n in range(1,10):
    print(f(n))
    '''
    # 7 一个嵌套很多层的列表,如l=[1,2,[3,[4,5,6,[7,8,[9,10,[11,12,13,[14,15]]]]]]],用递归取出所有的值
    '''
    l=[1,2,[3,[4,5,6,[7,8,[9,10,[11,12,13,[14,15]]]]]]]

    def f(lists):
    for x in lists:
    if type(x) is list:
    f(x)
    else:
    print(x)

    f(l)
    '''
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  • 原文地址:https://www.cnblogs.com/0B0S/p/12567430.html
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