python基礎(4)-元組&字典&字符串&隊列

元組(tuple)

1 #元組相對列表來講不一樣之處是隻讀不可寫 讀操做和列表一致
2 letter_tuple = ('a','b','c','d');
3 print(letter_tuple[0]);#result:a
4 print(letter_tuple[0:3]);#result:['a', 'b', 'c']
5 print(letter_tuple[3::-1]);#result:['c', 'b', 'a']

字典 (dictionary)

 1 addressDic = {'湖北':['武漢','襄陽'],'湖南':['長沙','岳陽']}
 2 for province in addressDic:
 3     cityList = addressDic[province];
 4     print(province,end = ":");
 5     for city in cityList:
 6         print(city,end = ";");
 7     print();
 8 #result:
 9     # 湖北: 武漢;襄陽;
10     # 湖南: 長沙;岳陽;

字符串 (string)

 1 letterStr = 'abcdefg';
 2 #重複輸出
 3 print(letterStr*2);#result:abcdefgabcdefg
 4 #切片
 5 print(letterStr[2:]);#result:cdefg
 6 #判斷是否存在
 7 print('abc' in letterStr);#result:True
 8 #格式化輸出
 9 print('abcd%s'%'efg');
10 
11 #string的內置方法
12 #獲取元素個數
13 print(letterStr.count('c'));#result:1
14 #字符串首字母大寫
15 print(letterStr.capitalize());#result:Abcdefg
16 #指定長度居中
17 print(letterStr.center(20,'-'));#result:------abcdefg-------
18 #是否以指定元素結尾
19 print(letterStr.endswith("g"));#result:True
20 #是否以指定元素開頭
21 print(letterStr.startswith("a"));#result:True
22 #指定tab空格長度
23 print("a\tb".expandtabs(tabsize=10));#result:a         b
24 #返回指定第一個元素索引值
25 print(letterStr.find('c'));#result:2
26 #格式化
27 print("hello {next}".format(next="world"));#result:hello world
28 print("name:{name};{age} years old".format_map({"name":"zhangsan","age":12}));#result:name:zhangsan;12 years old
29 #返回指定元素索引 不存在時會報錯
30 print(letterStr.find('c'));#result:2
31 #判斷只包含數字或字母
32 print("deqad#".isalnum());#result:False;
33 #判斷是不是整形數字
34 print('12'.isdigit());#result:True
35 #判斷是否不是非法命名
36 print("123a".isidentifier());#result:False
37 #判斷是否小寫
38 print(letterStr.islower());#result:True
39 #判斷是否大寫
40 print(letterStr.isupper());#result:False
41 #判斷是不是個空格
42 print(letterStr.isspace());#result:False
43 #判斷是否每一個單詞首字母大寫
44 print(letterStr.istitle())#result:False
45 #轉小寫
46 print(letterStr.lower());#result:abcdefg
47 #轉大寫
48 print(letterStr.upper());#result:ABCDEFG
49 #大小寫反轉
50 print(letterStr.swapcase());#result:ABCDEFG
51 #左填充
52 print(letterStr.ljust(20,'*'));#abcdefg*************
53 #右填充
54 print(letterStr.rjust(20,'*'));#*************abcdefg
55 #去首尾空白字符
56 print("  ade  \n".strip());#result:ade
57 #去首部空白字符
58 print("  ade  ".lstrip());#result:ade
59 #去尾部空白字符
60 print("  ade  \n".rstrip());#result:  ade
61 #替換
62 print(letterStr.replace('g','ghi'));#result:abcdefghi
63 #從右往左查找 返回實際位置
64 print("acbbbbcss".rfind('c'));#result:6
65 #切割字符串 返回列表
66 print(letterStr.split('d'));#result:['abc', 'efg']
67 #字符串內每一個單詞首字母大寫
68 print('hello world'.title());#result:Hello World

隊列(queen)

 1 import queue
 2 
 3 q = queue.Queue()
 4 q.put(1)
 5 q.put(2)
 6 q.put(3)
 7 print(q.qsize())  # 3 查看隊列元素個數
 8 print(q.get())  # 1
 9 print(q.get())  # 2
10 print(q.get())  # 3
11 print(q.qsize())  # 0
12 print(q.get())  # 阻塞

練習

三級聯動

 1 mainDic = {
 2     'a1':{
 3         'a1b1':{
 4             'a1b1c1':{},
 5             'a1b1c2':{},
 6             'a1b1c3':{}
 7         },
 8         'a1b2':{
 9             'a1b2c1': {},
10             'a1b2c2': {},
11             'a1b2c3': {}
12         },
13         'a1b3':{
14             'a1b3c1': {},
15             'a1b3c2': {},
16             'a1b3c3': {}
17         }
18     },
19     'a2':{
20         'a2b1': {
21             'a2b1c1': {},
22             'a2b1c2': {},
23             'a2b1c3': {}
24         },
25         'a2b2': {
26             'a2b2c1': {},
27             'a2b2c2': {},
28             'a2b2c3': {}
29         },
30         'a2b3': {
31             'a2b3c1': {},
32             'a2b3c2': {},
33             'a2b3c3': {}
34         }
35     },
36     'a3':{
37         'a3b1': {
38             'a3b1c1': {},
39             'a3b1c2': {},
40             'a3b1c3': {}
41         },
42         'a3b2': {
43             'a3b2c1': {},
44             'a3b2c2': {},
45             'a3b2c3': {}
46         },
47         'a3b3': {
48             'a3b3c1': {},
49             'a3b3c2': {},
50             'a3b3c3': {}
51         }
52     }
53 };
54 currentLayer = mainDic;
55 parentLayers = [];
56 while True:
57     for item in currentLayer:
58         print(item);
59     choose = input('input your choose:');
60     if(choose in currentLayer):
61         if not currentLayer[choose]:
62             print('last layer');
63             continue;
64         parentLayers.append(currentLayer);
65         currentLayer = currentLayer[choose];
66     elif choose=='e':
67         currentLayer = parentLayers.pop();
68     elif choose=='exit':
69         break;
70     else:
71         print('該項不存在');
72 
73 #result:
74     # >>a1
75     # >>a2
76     # >>a3
77     # >>input your choose:a2
78     # >>a2b1
79     # >>a2b2
80     # >>a2b3
81     # >>input your choose:a2b2
82     # >>a2b2c1
83     # >>a2b2c2
84     # >>a2b2c3
85     # >>input your choose:e
86     # >>a2b1
87     # >>a2b2
88     # >>a2b3
89     # >>input your choose:e
90     # >>a1
91     # >>a2
92     # >>a3
93     # >>input your choose:exit

擴展

批量賦值

1 a,b = [1,2];
2 print(a);#result:1
3 print(b);#result:2

enumerate(iterable:遍歷對象,start:起始下標) 

該函數用於將一個可遍歷的數據對象(如列表、元組或字符串)組合爲一個索引序列，同時列出數據和數據下標，通常用在 for 循環當中。

letter_tuple = ['a','b','c','d','e'];
for index,value in enumerate(letter_tuple,1):
    print(index,value);
#result:
    # (1, 1)
    # (2, 2)
    # (3, 3)
    # (4, 4)
    # (5, 5)

取序列長度

1 letterStr = 'abcdefg';
2 letterList = ['a','b','c','d','e','f','g'];
3 print(len(letterStr));#result:7
4 print(len(letterList));#result:7

可把序列當作判斷條件,爲空時返回False,反之True

1 list = [];
2 if list:print('True');
3 else:print('False');
4 #result:False;
5 list.append(1);
6 if list:print('True');
7 else:print('False')
8 #result:True