python之公共操作符

 1 str1 = ‘aa‘
 2 str2 = ‘bb‘
 3 
 4 list1 = [1, 2]
 5 list2 = [10, 20]
 6 
 7 t1 = (1, 2)
 8 t2 = (10, 20)
 9 
10 dict1 = {‘name‘: ‘Python‘}
11 dict2 = {‘age‘: 30}
12 
13 # +: 合并
14 print(str1 + str2)
15 print(list1 + list2)
16 print(t1 + t2)
17 
18 # print(dict1 + dict2)  # 报错：字典不支持合并运算

1 aabb
2 [1, 2, 10, 20]
3 (1, 2, 10, 20)

 1 str1 = ‘a‘
 2 list1 = [‘hello‘]
 3 t1 = (‘world‘,)
 4 
 5 # *:复制
 6 print(str1 * 5)
 7 
 8 # 打印10个-：
 9 print(‘-‘ * 10)
10 
11 print(list1 * 5)
12 
13 print(t1 * 5)

1 aaaaa
2 ----------
3 [‘hello‘, ‘hello‘, ‘hello‘, ‘hello‘, ‘hello‘]
4 (‘world‘, ‘world‘, ‘world‘, ‘world‘, ‘world‘)

 1 str1 = ‘abcd‘
 2 list1 = [10, 20, 30, 40]
 3 t1 = (100, 200, 300, 400)
 4 dict1 = {‘name‘: ‘Python‘, ‘age‘: 30}
 5 
 6 # in 和 not in
 7 # 1. 字符a是否存在
 8 print(‘a‘ in str1)
 9 print(‘a‘ not in str1)
10 
11 # 2. 数据10是否存在
12 print(10 in list1)
13 print(10 not in list1)
14 
15 # 3. 100是否存在
16 print(100 not in t1)
17 print(100 in t1)
18 
19 # 4. name是否存在
20 print(‘name‘ in dict1)
21 print(‘name‘ not in dict1)
22 print(‘name‘ in dict1.keys())
23 print(‘name‘ in dict1.values())

 1 True
 2 False
 3 True
 4 False
 5 False
 6 True
 7 True
 8 False
 9 True
10 False

 1 str1 = ‘abcdefg‘
 2 list1 = [10, 20, 30, 40, 50]
 3 t1 = (10, 20, 30, 40, 50)
 4 s1 = {10, 20, 30, 40, 50}
 5 dict1 = {‘name‘: ‘TOM‘, ‘age‘: 18}
 6 print(len(str1))
 7 print(len(list1))
 8 print(len(t1))
 9 print(len(s1))
10 print(len(dict1))

1 7
2 5
3 5
4 5
5 2

 1 str1 = ‘abcdefg‘
 2 list1 = [10, 20, 30, 40, 50]
 3 t1 = (10, 20, 30, 40, 50)
 4 s1 = {10, 20, 30, 40, 50}
 5 dict1 = {‘name‘: ‘TOM‘, ‘age‘: 18}
 6 
 7 # del 目标 或del(目标)
 8 #del str
 9 #print(str1)  str不存在，报错
10 
11 # del(list1)
12 print(list1)
13 del(list1[0])
14 print(list1)
15 
16 #del s1
17 #print(s1)
18 
19 #del dict1
20 #print(dict1)
21 del dict1[‘name‘]
22 print(dict1)

 1 str1 = ‘abcdefg‘
 2 list1 = [10, 20, 30, 40, 50]
 3 
 4 # max() : 最大值
 5 # print(max(str1))
 6 # print(max(list1))
 7 
 8 # min() ： 最小值
 9 print(min(str1))
10 print(min(list1))

 1 # range(start, end, step)
 2 # print(range(1, 10, 1))
 3 # for i in range(1, 10, 1):
 4 #     print(i)
 5 
 6 # for i in range(1, 10):
 7 #     print(i)
 8 
 9 # for i in range(1, 10, 2):
10 #     print(i)
11 
12 
13 for i in range(10):
14     print(i)
15 
16 # 1. 如果不写开始，默认从0开始
17 # 2. 如果不写步长，默认为1

1 list1 = [‘a‘, ‘b‘, ‘c‘, ‘d‘, ‘e‘]
2 
3 # enumerate 返回结果是元组，元组第一个数据是原迭代对象的数据对应的下标，元组第二个数据是原迭代对象的数据
4 # for i in enumerate(list1):
5 #     print(i)
6 
7 for i in enumerate(list1, start=2):
8     print(i)

1 (2, ‘a‘)
2 (3, ‘b‘)
3 (4, ‘c‘)
4 (5, ‘d‘)
5 (6, ‘e‘)