Python 字典，,Python 字典1

Python 字典，,Python 字典1

Python 字典

1. 遍历字典

遍历字典的键

dict1 = {‘a‘: 1, ‘b‘: 2, ‘c‘: 3, ‘d‘: 4}for key in dict1.keys():    print(key)# 输出：a b c d

遍历字典的值

dict1 = {‘a‘: 1, ‘b‘: 2, ‘c‘: 3, ‘d‘: 4}for value in dict1.values():    print(value)dict1.get(‘a‘)dict1.get(‘b‘)dict1.get(‘c‘)# 输出：1 2 3 4

遍历字典的键值对

dict1 = {‘a‘: 1, ‘b‘: 2, ‘c‘: 3, ‘d‘: 4}for k, v in dict1.items():    print(k, ": ", v)# 输出：a :  1b :  2c :  3d :  4

更新字典

dict1 = {‘a‘: 1, ‘b‘: 2, ‘c‘: 3, ‘d‘: 4}dict2 = {‘e‘: 5}dict1.update(dict2)print(dict1)# 输出：{‘a‘: 1, ‘b‘: 2, ‘c‘: 3, ‘d‘: 4, ‘e‘: 5}

删除字典所有键值对

dict1 = {‘a‘: 1, ‘b‘: 2, ‘c‘: 3, ‘d‘: 4, ‘e‘: 5}dict1.clear()print(dict1)# 输出：{}

删除最后一个键值对

dict1 = {‘a‘: 1, ‘b‘: 2, ‘c‘: 3, ‘d‘: 4, ‘e‘: 5}dict1.popitem()print(dict1)# 输出：{‘a‘: 1, ‘b‘: 2, ‘c‘: 3, ‘d‘: 4}

比较两个字典的差异

dict1 = {‘a‘: 1, ‘b‘: 2, ‘c‘: 3, ‘d‘: 4}dict2 = {‘a‘: 1, ‘b‘: 2, ‘c‘: 5, ‘e‘: 6}differ = set(dict1.items()) ^ set(dict2.items())"""输出所有的差异"""print(differ)# 输出:{(‘c‘, 3), (‘e‘, 6), (‘c‘, 5), (‘d‘, 4)}"""获取两个字典key的交集"""diff = dict1.keys() & dict2print(diff)# 输出：{‘a‘, ‘c‘, ‘b‘}"""输出相同key下的不同value"""diff_vals = [(k, dict1[k], dict2[k]) for k in diff if dict1[k] != dict2[k]]print(diff_vals)# 输出：[(‘c‘, 3, 5)]

直接赋值何copy的区别

Python 字典