python之公共操作符,,摘要:本文主要介绍了


摘要:本文主要介绍了一些公共运算符、公共方法的操作方式。

1、公共运算符

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“+”:

 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

操作结果如下:

1 aabb2 [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)

操作结果如下:

1 aaaaa2 ----------3 [‘hello‘, ‘hello‘, ‘hello‘, ‘hello‘, ‘hello‘]4 (‘world‘, ‘world‘, ‘world‘, ‘world‘, ‘world‘)

“in”和“not in”:

 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())

操作结果如下:

 1 True 2 False 3 True 4 False 5 False 6 True 7 True 8 False 9 True10 False

2、公共方法

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len():

 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))

操作结果如下:

1 72 53 54 55 2

del和del():

 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 s117 #print(s1)18 19 #del dict120 #print(dict1)21 del dict1[‘name‘]22 print(dict1)

max()和min():

 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))

range(start, end, step):

 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

enumerate():

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)

操作结果如下:

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

python之公共操作符

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