• Python学习之路4——Python列表、元组、字典和集合


    1、Python列表

    列表是Python中最基本的数据结构,通过列表可以对数据实现最方便的存储、修改等操作,列表是有顺序的。

    定义列表

    1 names = ['Vison','Tenglan','Eric']

    通过下标访问列表中的元素,下标从0开始计数,下标取负数可以从列表结尾访问元素。

     1 #!/user/bin/env ptyhon
     2 # -*- coding:utf-8 -*-
     3 # Author: VisonWong
     4 
     5 names = ['Vison','Tenglan','Eric']
     6 
     7 print('Name1:',names[0])
     8 print('Name3:',names[2])
     9 print('Name_end:',names[-1])
    10 print('Name2:',names[-2])
    11 
    12 
    13 # Name1: Vison
    14 # Name3: Eric
    15 # Name_end: Eric
    16 # Name2: Tenglan

     列表切片:

     1 Python 3.6.2 (v3.6.2:5fd33b5, Jul  8 2017, 04:14:34) [MSC v.1900 32 bit (Intel)] on win32
     2 Type "copyright", "credits" or "license()" for more information.
     3 
     4 
     5 >>> names = ["Vison","Tenglan","Eric","Rain","Tom","Amy"]
     6 >>> names[1:4]   #取下标1至下标4之间的元素,包括1,不包括4
     7 ['Tenglan', 'Eric', 'Rain']
     8 >>> names[1:-1]   #取下标1至结尾之间的元素,包括1,不包括结尾
     9 ['Tenglan', 'Eric', 'Rain', 'Tom']
    10 >>> names[:3]     #如果是头开始取,0可以忽略
    11 ['Vison', 'Tenglan', 'Eric']
    12 >>> names[3:]     #如果想取最后一个,必须不能写-1,只能这么写
    13 ['Rain', 'Tom', 'Amy']
    14 >>> names[3:-1]   #这样-1就不会被包含了
    15 ['Rain', 'Tom']
    16 >>> names[0::2]   #后面的2代表每隔一个元素,取一下
    17 ['Vison', 'Eric', 'Tom']
    18 >>> names[::2]    #和上句效果一样
    19 ['Vison', 'Eric', 'Tom']

    列表追加:

    1 Python 3.6.2 (v3.6.2:5fd33b5, Jul  8 2017, 04:14:34) [MSC v.1900 32 bit (Intel)] on win32
    2 Type "copyright", "credits" or "license()" for more information.
    3  
    4 >>> names = ["Vison","Tenglan","Eric","Rain","Tom","Amy"]
    5 >>> names
    6 ['Vison', 'Tenglan', 'Eric', 'Rain', 'Tom', 'Amy']
    7 >>> names.append("我是新来的")  #append方法用来在列表末尾加入新元素
    8 >>> names
    9 ['Vison', 'Tenglan', 'Eric', 'Rain', 'Tom', 'Amy', '我是新来的']

    列表插入:

     1 Python 3.6.2 (v3.6.2:5fd33b5, Jul  8 2017, 04:14:34) [MSC v.1900 32 bit (Intel)] on win32
     2 Type "copyright", "credits" or "license()" for more information.
     3 
     4 
     5 >>> names
     6 ['Vison', 'Tenglan', 'Eric', 'Rain', 'Tom', 'Amy', '我是新来的']
     7 >>> names.insert(2,'强行从Tenglan后面插入')  #insert方法用来在指定下标处插入新元素
     8 >>> names
     9 ['Vison', 'Tenglan', '强行从Tenglan后面插入', 'Eric', 'Rain', 'Tom', 'Amy', '我是新来的']
    10 >>> names.insert(5,'强行从Rain后面插入')
    11 >>> names
    12 ['Vison', 'Tenglan', '强行从Tenglan后面插入', 'Eric', 'Rain', '强行从Rain后面插入', 'Tom', 'Amy', '我是新来的']

    列表修改:

    1 Python 3.6.2 (v3.6.2:5fd33b5, Jul  8 2017, 04:14:34) [MSC v.1900 32 bit (Intel)] on win32
    2 Type "copyright", "credits" or "license()" for more information.
    3 
    4 >>> names
    5 ['Vison', 'Tenglan', '强行从Tenglan后面插入', 'Eric', 'Rain', '强行从Rain后面插入', 'Tom', 'Amy', '我是新来的']
    6 >>> names[2] = '该换人了'
    7 >>> names
    8 ['Vison', 'Tenglan', '该换人了', 'Eric', 'Rain', '强行从Rain后面插入', 'Tom', 'Amy', '我是新来的']

    列表删除:

     1 Python 3.6.2 (v3.6.2:5fd33b5, Jul  8 2017, 04:14:34) [MSC v.1900 32 bit (Intel)] on win32
     2 Type "copyright", "credits" or "license()" for more information.
     3 
     4 
     5 >>> names
     6 ['Vison', 'Tenglan', '该换人了', 'Eric', 'Rain', '强行从Rain后面插入', 'Tom', 'Amy', '我是新来的']
     7 >>> del names[2]
     8 >>> names
     9 ['Vison', 'Tenglan', 'Eric', 'Rain', '强行从Rain后面插入', 'Tom', 'Amy', '我是新来的']
    10 >>> del names[4]
    11 >>> names
    12 ['Vison', 'Tenglan', 'Eric', 'Rain', 'Tom', 'Amy', '我是新来的']
    13 >>> names.remove('Eric')  #remove方法删除指定元素
    14 >>> names
    15 ['Vison', 'Tenglan', 'Rain', 'Tom', 'Amy', '我是新来的']
    16 >>> names.pop()  #删除列表最后一个元素
    17 '我是新来的'
    18 >>> names
    19 ['Vison', 'Tenglan', 'Rain', 'Tom', 'Amy']

    列表拓展:

     1 Python 3.6.2 (v3.6.2:5fd33b5, Jul  8 2017, 04:14:34) [MSC v.1900 32 bit (Intel)] on win32
     2 Type "copyright", "credits" or "license()" for more information.
     3 
     4 
     5 >>> names
     6 ['Vison', 'Tenglan', 'Rain', 'Tom', 'Amy']
     7 >>> b = [1,2,3]
     8 >>> names.extend(b)
     9 >>> names
    10 ['Vison', 'Tenglan', 'Rain', 'Tom', 'Amy', 1, 2, 3]

    列表复制:

     1 >>> import copy
     2 >>> origin = [1, 2, [3, 4]]
     3 #origin 里边有三个元素:1, 2,[3, 4]
     4 >>> cop1 = copy.copy(origin)
     5 >>> cop2 = copy.deepcopy(origin)
     6 >>> cop1 == cop2
     7 True
     8 >>> cop1 is cop2
     9 False 
    10 #cop1 和 cop2 看上去相同,但已不再是同一个object
    11 >>> origin[2][0] = "hey!" 
    12 >>> origin
    13 [1, 2, ['hey!', 4]]
    14 >>> cop1
    15 [1, 2, ['hey!', 4]]
    16 >>> cop2
    17 [1, 2, [3, 4]]
    18 #把origin内的子list [3, 4] 改掉了一个元素,观察 cop1 和 cop2

    copy()为浅复制。deepcopy()为深复制。

    我们寻常意义的复制就是深复制,即将被复制对象完全再复制一遍作为独立的新个体单独存在,所以改变原有被复制对象不会对已经复制出来的新对象产生影响。 

    而浅复制并不会产生一个独立的对象单独存在,他只会复制第一层数据,对于嵌套列表只会复制数据指针。

    所以当被复制对象嵌套列表里的元素发生改变时,另一个复制对象也会随之改变。

    对于简单的 object,用 shallow copy 和 deep copy 没区别。

    复杂的 object, 如 list 中套着 list 的情况,shallow copy 中的 子list,并未从原 object 真的「独立」出来。

    也就是说,如果你改变原 object 的子 list 中的一个元素,你的 copy 就会跟着一起变。

    列表统计:

    1 Python 3.6.2 (v3.6.2:5fd33b5, Jul  8 2017, 04:14:34) [MSC v.1900 32 bit (Intel)] on win32
    2 Type "copyright", "credits" or "license()" for more information.
    3 
    4 >>> names = ['Alex', 'Tenglan', 'Amy', 'Tom', 'Amy', 1, 2, 3]
    5 >>> names
    6 ['Alex', 'Tenglan', 'Amy', 'Tom', 'Amy', 1, 2, 3]
    7 >>> names.count('Amy')
    8 2

     列表排序和翻转:

     1 Python 3.6.2 (v3.6.2:5fd33b5, Jul  8 2017, 04:14:34) [MSC v.1900 32 bit (Intel)] on win32
     2 Type "copyright", "credits" or "license()" for more information.
     3 
     4 
     5 >>> names = ['Vison', 'Tenglan', 'Amy', 'Tom', 'Amy', 1, 2, 3]
     6 >>> names.sort()  #排序
     7 Traceback (most recent call last):
     8   File "<pyshell#2>", line 1, in <module>
     9     names.sort()  #排序
    10 TypeError: '<' not supported between instances of 'int' and 'str'  #3.0不支持不同数据类型排序
    11 >>> names[-3] = '1'
    12 >>> names[-2] = '2'
    13 >>> names[-1] = '3'
    14 >>> names
    15 ['Amy', 'Amy', 'Tenglan', 'Tom', 'Vison', '1', '2', '3']
    16 >>> names.sort()
    17 >>> names
    18 ['1', '2', '3', 'Amy', 'Amy', 'Tenglan', 'Tom', 'Vison']
    19 
    20  
    21 >>> names.reverse()  #翻转
    22 >>> names
    23 ['Vison', 'Tom', 'Tenglan', 'Amy', 'Amy', '3', '2', '1']

     列表获取下标:

    1 Python 3.6.2 (v3.6.2:5fd33b5, Jul  8 2017, 04:14:34) [MSC v.1900 32 bit (Intel)] on win32
    2 Type "copyright", "credits" or "license()" for more information.
    3 
    4 >>> names
    5 ['Vison', 'Tom', 'Tenglan', 'Amy', 'Amy', '3', '2', '1']
    6 >>> names.index('Amy')
    7

      列表的遍历: 

     1 # !/user/bin/env ptyhon
     2 # -*- coding:utf-8 -*-
     3 # Author: VisonWong
     4 
     5 names = ['Vison', 'Tenglan', 'Eric']
     6 for name in names:
     7     print(name)    
     8 
     9 # Vison
    10 # Tenglan
    11 # Eric
    12 
    13 for index, name in enumerate(names):
    14     print(index, name)
    15 
    16 # 0 Vison
    17 # 1 Tenglan
    18 # 2 Eric 

    2、Python元组

    元组其实跟列表差不多,也是存一组数,只不是它一旦创建,便不能再修改,所以又叫只读列表。

    1 Python 3.6.2 (v3.6.2:5fd33b5, Jul  8 2017, 04:14:34) [MSC v.1900 32 bit (Intel)] on win32
    2 Type "copyright", "credits" or "license()" for more information.
    3 
    4 >>> names = ('Vison', 'jack', 'eric')
    5 >>> names
    6 ('Vison', 'jack', 'eric')

    元组只有2个方法,一个是count,一个是index。

    1 ##count        #统计元组字符出现的次数   
    2 name =  ('wupeiqi', 'alex','lzl')
    3 print(name.count('alex'))             
    4 # 1
    5 ##index             #查看字符串所在的索引位置
    6 name =  ('wupeiqi', 'alex','lzl')
    7 print(name.index('lzl'))               
    8 # 2

      元组的遍历:

     1 #!/user/bin/env ptyhon
     2 # -*- coding:utf-8 -*-
     3 # Author: VisonWong
     4 
     5 names = ('Vison','Tenglan','Eric')
     6 for name in names:
     7     print(name)
     8     
     9 
    10 # Vison
    11 # Tenglan
    12 # Eric 

    3、Python字典

    字典一种key - value 的数据类型,使用就像我们上学用的字典,通过笔划、字母来查对应页的详细内容。

    定义字典:

     1 Python 3.6.2 (v3.6.2:5fd33b5, Jul  8 2017, 04:14:34) [MSC v.1900 32 bit (Intel)] on win32
     2 Type "copyright", "credits" or "license()" for more information.
     3 
     4 
     5 >>> info = {
     6     'stu1': "Vison Wong1",
     7     'stu2': "Vison Wong2",
     8     'stu3': "Vison Wong3",
     9 }
    10 >>> info
    11 {'stu1': 'Vison Wong1', 'stu2': 'Vison Wong2', 'stu3': 'Vison Wong3'}

    字典的特性:

      • dict是无序的
      • key必须是唯一的,so 天生去重

    字典增加:

    1 Python 3.6.2 (v3.6.2:5fd33b5, Jul  8 2017, 04:14:34) [MSC v.1900 32 bit (Intel)] on win32
    2 Type "copyright", "credits" or "license()" for more information.
    3 
    4 >>> info
    5 {'stu1': 'Vison Wong1', 'stu2': 'Vison Wong2', 'stu3': 'Vison Wong3'}
    6 >>> info['stu4'] = 'Vison Wong4'
    7 >>> info
    8 {'stu1': 'Vison Wong1', 'stu2': 'Vison Wong2', 'stu3': 'Vison Wong3', 'stu4': 'Vison Wong4'}

    字典修改:

    1 Python 3.6.2 (v3.6.2:5fd33b5, Jul  8 2017, 04:14:34) [MSC v.1900 32 bit (Intel)] on win32
    2 Type "copyright", "credits" or "license()" for more information.
    3 
    4 
    5 >>> info
    6 {'stu1': 'Vison Wong1', 'stu2': 'Vison Wong2', 'stu3': 'Vison Wong3', 'stu4': 'Vison Wong4'}
    7 >>> info['stu1'] = 'Vison Wong1_revised'
    8 >>> info
    9 {'stu1': 'Vison Wong1_revised', 'stu2': 'Vison Wong2', 'stu3': 'Vison Wong3', 'stu4': 'Vison Wong4'}

    字典删除:

     1 Python 3.6.2 (v3.6.2:5fd33b5, Jul  8 2017, 04:14:34) [MSC v.1900 32 bit (Intel)] on win32
     2 Type "copyright", "credits" or "license()" for more information.
     3 
     4 >>> info
     5 {'stu1': 'Vison Wong1_revised', 'stu2': 'Vison Wong2', 'stu3': 'Vison Wong3', 'stu4': 'Vison Wong4'}
     6 >>> info.pop('stu1')
     7 'Vison Wong1_revised'
     8 >>> info
     9 {'stu2': 'Vison Wong2', 'stu3': 'Vison Wong3', 'stu4': 'Vison Wong4'}
    10 >>> del info['stu3']
    11 >>> info
    12 {'stu2': 'Vison Wong2', 'stu4': 'Vison Wong4'}

     字典查找: 

     1 Python 3.6.2 (v3.6.2:5fd33b5, Jul  8 2017, 04:14:34) [MSC v.1900 32 bit (Intel)] on win32
     2 Type "copyright", "credits" or "license()" for more information.
     3 
     4 
     5 >>> info = {
     6     'stu1': 'Vison Wong1',
     7     'stu2': 'Vison Wong2',
     8     'stu3': 'Vison Wong3',
     9     'stu4': 'Vison Wong4'
    10     }
    11 >>> info
    12 {'stu1': 'Vison Wong1', 'stu2': 'Vison Wong2', 'stu3': 'Vison Wong3', 'stu4': 'Vison Wong4'}
    13 >>> 'stu2' in info
    14 True
    15 >>> info.get('stu2')
    16 'Vison Wong2'
    17 >>> info['stu2']
    18 'Vison Wong2'

     字典常见用法:

     1 Python 3.6.2 (v3.6.2:5fd33b5, Jul  8 2017, 04:14:34) [MSC v.1900 32 bit (Intel)] on win32
     2 Type "copyright", "credits" or "license()" for more information.
     3 >>> info = {
     4     'stu1': 'Vison Wong1',
     5     'stu2': 'Vison Wong2',
     6     'stu3': 'Vison Wong3',
     7     'stu4': 'Vison Wong4'
     8     }
     9 >>> info
    10 {'stu1': 'Vison Wong1', 'stu2': 'Vison Wong2', 'stu3': 'Vison Wong3', 'stu4': 'Vison Wong4'}
    11 >>> #取值
    12 >>> info.values() 
    13 dict_values(['Vison Wong1', 'Vison Wong2', 'Vison Wong3', 'Vison Wong4'])
    14 >>> #取键
    15 >>> info.keys()    
    16 dict_keys(['stu1', 'stu2', 'stu3', 'stu4'])
    17 >>> # setdefault() 函数如果键不存在于字典中,将会添加键并将值设为默认值。
    18 >>> # 如果字典中包含有给定键,则返回该键已有键值,否则返回为该键设置的值。
    19 >>> info.setdefault('stu5','Vison Wong5')
    20 'Vison Wong5'
    21 >>> info
    22 {'stu1': 'Vison Wong1', 'stu2': 'Vison Wong2', 'stu3': 'Vison Wong3', 'stu4': 'Vison Wong4', 'stu5': 'Vison Wong5'}
    23 >>> info.setdefault('stu1','Vison Wong1_revised')
    24 'Vison Wong1'
    25 >>> info
    26 {'stu1': 'Vison Wong1', 'stu2': 'Vison Wong2', 'stu3': 'Vison Wong3', 'stu4': 'Vison Wong4', 'stu5': 'Vison Wong5'}
    27 >>> # dict.update(dict2) 把字典dict2的键/值对更新到dict里
    28 >>> info1 = {
    29     'stu1' : 'Vison Wong1_revised',
    30     'stu6' : 'Vison Wong6'
    31     }
    32 >>> info.update(info1)
    33 >>> info
    34 {'stu1': 'Vison Wong1_revised', 'stu2': 'Vison Wong2', 'stu3': 'Vison Wong3', 'stu4': 'Vison Wong4', 'stu5': 'Vison Wong5', 'stu6': 'Vison Wong6'}
    35 >>> # items() 函数以列表返回可遍历的(键, 值) 元组数组
    36 >>> info.items()
    37 dict_items([('stu1', 'Vison Wong1_revised'), ('stu2', 'Vison Wong2'), ('stu3', 'Vison Wong3'), ('stu4', 'Vison Wong4'), ('stu5', 'Vison Wong5'), ('stu6', 'Vison Wong6')])

    字典遍历:

     1 info_dic = {'stu1101': "TengLan Wu",'stu1102': "LongZe Luola",'stu1103': "XiaoZe Maliya",}
     2 for stu_nu in info_dic:
     3     print(stu_nu,info_dic[stu_nu])             #循环默认提取的是key
     4 #stu1103 XiaoZe Maliya
     5 #stu1101 TengLan Wu
     6 #stu1102 LongZe Luola
     7 for k,v in info_dic.items():                  #先把dict生成list,数据量大的时候费时,不建议使用
     8     print(k,v)
     9 #stu1103 XiaoZe Maliya
    10 #stu1101 TengLan Wu
    11 #stu1102 LongZe Luola 

    补充:

     1 dic = {'k1':'v1','k2':'v2','k3':'v3'}
     2  
     3 for key,value in dic.items():               #错误的方式
     4     if key == 'k2':
     5         del dic[key]
     6 # RuntimeError: dictionary changed size during iteration           #字典在迭代的时候不能改变其长度
     7  
     8 print(dic.keys())           # 迭代器
     9 # dict_keys(['k3', 'k2', 'k1'])
    10 for key in list(dic.keys()):
    11     if key == 'k2':
    12         del dic[key]

    多级字典嵌套及操作:

     1 Python 3.6.2 (v3.6.2:5fd33b5, Jul  8 2017, 04:14:34) [MSC v.1900 32 bit (Intel)] on win32
     2 Type "copyright", "credits" or "license()" for more information.
     3 
     4 
     5 >>> menu = {
     6     '河南': {
     7         '郑州': ['金水区', '二七区', '惠济区', '中原区', '上街区'],
     8         '洛阳': ['涧西区', '西工区', '老城区', '洛龙区', '吉利区'],
     9         '三门峡' : ['灵宝市', '卢氏', '义马市', '陕县']
    10     },
    11     '陕西': {
    12         '西安': ['碑林区', '莲湖区', '雁塔区', '未央区', '灞桥区'],
    13         '渭南': ['临渭区', '华阴市', '韩城', '华县', '潼关'],
    14         '宝鸡': ['涧西区', '西工区', '老城区', '洛龙区', '吉利区']
    15     }
    16 }
    17 
    18 
    19 >>> menu['陕西']['西安']
    20 ['碑林区', '莲湖区', '雁塔区', '未央区', '灞桥区']

    4、Python集合

    集合是一个无序的,不重复的数据组合,它的主要作用如下:

      • 去重,把一个列表变成集合,就自动去重了
      • 关系测试,测试两组数据之前的交集、差集、并集等关系

    集合定义:

     1 Python 3.6.2 (v3.6.2:5fd33b5, Jul  8 2017, 04:14:34) [MSC v.1900 32 bit (Intel)] on win32
     2 Type "copyright", "credits" or "license()" for more information.
     3 
     4 >>> set1 = {1,2,3,5,7,9}
     5 >>> set1
     6 {1, 2, 3, 5, 7, 9}
     7 >>> type(set1)
     8 <class 'set'>
     9 >>> set2 = {2,4,6,8}
    10 >>> set2
    11 {8, 2, 4, 6}

    集合常见用法:

     1 Python 3.6.2 (v3.6.2:5fd33b5, Jul  8 2017, 04:14:34) [MSC v.1900 32 bit (Intel)] on win32
     2 Type "copyright", "credits" or "license()" for more information.
     3 
     4 >>> set1
     5 {1, 2, 3, 5, 7, 9}
     6 >>> set2
     7 {8, 2, 4, 6}
     8 >>> #   交集
     9 >>> set1.intersection(set2)
    10 {2}
    11 >>> #   并集
    12 >>> set1.union(set2)
    13 {1, 2, 3, 4, 5, 6, 7, 8, 9}
    14 >>> #   差集,在set1中,不在set2中
    15 >>> set1.difference(set2)
    16 {1, 3, 5, 7, 9}
    17 >>> #   对称差集,在set1或set2中,但不会同时出现在二者中
    18 >>> set1.symmetric_difference(set2)
    19 {1, 3, 4, 5, 6, 7, 8, 9}
    20 >>> #   添加一项
    21 >>> set2.add(0)
    22 >>> set2
    23 {0, 2, 4, 6, 8}
    24 >>> #  添加多项
    25 >>> set1.update([11,13])
    26 >>> set1
    27 {1, 2, 3, 5, 7, 9, 11, 13}
    28 >>> #  删除一个元素
    29 >>> set1.remove(13)
    30 >>> set1
    31 {1, 2, 3, 5, 7, 9, 11}
    32 >>> #  测试集合长度
    33 >>> len(set1)
    34 7
    35 >>> #  测试set1是否为set2子集
    36 >>> set1.issubset(set2)
    37 False
    38 >>> #  测试set1是否为set2父集
    39 >>> set1.issuperset(set2)
    40 False

    5、 列表、元组、字典的相互转换

    列表的转换:

     1 Python 3.6.2 (v3.6.2:5fd33b5, Jul  8 2017, 04:14:34) [MSC v.1900 32 bit (Intel)] on win32
     2 Type "copyright", "credits" or "license()" for more information.
     3 
     4 >>> # 列表转元组
     5 list1 = ['value1','value2','value3']
     6 >>> tuple(list1)
     7 ('value1', 'value2', 'value3')
     8 >>> # 列表转集合(去重)
     9 >>> set(list1)
    10 {'value2', 'value3', 'value1'}
    11 >>> # 两个列表转字典
    12 >>> list2 = ['key1','key2','key3']
    13 >>> dict(zip(list2,list1))
    14 {'key1': 'value1', 'key2': 'value2', 'key3': 'value3'}
    15 >>> # 嵌套列表转字典
    16 >>> list3 = [['key1','value1'],['key2','value2'],['key3','value3']]
    17 >>> dict(list3)
    18 {'key1': 'value1', 'key2': 'value2', 'key3': 'value3'}
    19 >>> # 列表转字符串
    20 >>> ''.join(list1)
    21 'value1value2value3'

     元组的转换

    元组的转换与列表相似,方法通用。

    1 Python 3.6.2 (v3.6.2:5fd33b5, Jul  8 2017, 04:14:34) [MSC v.1900 32 bit (Intel)] on win32
    2 Type "copyright", "credits" or "license()" for more information.
    3 >>> # 元组转列表
    4 >>> tuple1 =('value1','value2','value3')
    5 >>> list(tuple1)
    6 ['value1', 'value2', 'value3']

     字典的转换:

     1 Python 3.6.2 (v3.6.2:5fd33b5, Jul  8 2017, 04:14:34) [MSC v.1900 32 bit (Intel)] on win32
     2 Type "copyright", "credits" or "license()" for more information.
     3 >>> 
     4 >>> dict1 = {
     5     'key1':'value1',
     6     'key2':'value2',
     7     'key3':'value3'
     8     }
     9 >>> # 将字典的key转换为列表
    10 >>> list(dict1)
    11 ['key1', 'key2', 'key3']
    12 >>> # 将字典的value转换为列表15 >>> list(dict1.values())
    16 ['value1', 'value2', 'value3']
    17 >>> # 将字典转换为字符串
    18 >>> str(dict1)
    19 "{'key1': 'value1', 'key2': 'value2', 'key3': 'value3'}"
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  • 原文地址:https://www.cnblogs.com/visonwong/p/8676737.html
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