2: 'ball'} # 创建 key 值为 string 的字典 my_dict3 = {'name1': 'apple', 'name2': 'ball'} # 创建 key 值为 数字 和 string 混合的字典 my_dict4 = {'name': 'apple', 1: [2, 4, 3]} # 用 dict() 函数创建字典 my_dict5 = dict({1:'apple', 2:'ball'}) # ...
字典推导式(dict comprehension):形如{key:value for key, value in iterable}这样的推导式,其中iterable中每个元素为包含两个元素的元组,并且每个元组的第一个元素为可哈希对象。字典推导式的结果为字典。 集合推导式(set comprehension):形如{item for item in iterable}这样的推导式,其中iterable中每个元素都是可...
字典推导式(dict comprehension):形如{key:value for key, value in iterable}这样的推导式,其中iterable中每个元素为包含两个元素的元组,并且每个元组的第一个元素为可哈希对象。字典推导式的结果为字典。 集合推导式(set comprehension):形如{item for item in iterable}这样的推导式,其中iterable中每个元素都是可...
>>> int_object = 1 >>> %timeit map(int_object.__add__, long_list) 10000 loops, best ...
Using list comprehension is an efficient way to return both the key and the value together in a single operation without the need to look up the key separately. For example: addresses = [key + " => " + value for key, value in address_book.items()] print(addresses) We get: ['Alic...
字典推导式(dict comprehension):形如{key:value for key, value in iterable}这样的推导式,其中iterable中每个元素为包含两个元素的元组,并且每个元组的第一个元素为可哈希对象。字典推导式的结果为字典。 集合推导式(set comprehension):形如{item for item in iterable}这样的推导式,其中iterable中每个元素都是可...
In the following sections, you’ll dive deeper into how to create Python dictionaries using literals and the dict() constructor.Dictionary LiteralsYou can define a dictionary by enclosing a comma-separated series of key-value pairs in curly braces ({}). To separate the keys from their values,...
Specified sort keys to sort a dictionary by value, key, or nested attribute Used dictionary comprehensions and the dict() constructor to rebuild your dictionaries Considered whether a sorted dictionary is the right data structure for your key-value data You’re now ready to not only sort dictiona...
A set is an unordered collection of unique elements. You can think of them like dicts, but keys only, no values. 基本操作如下图: List, Set and Dict Comprehensions# list comprehension:[expr for val in collection if condition] dict comprehension:{key-expr : value-expr for value in collectio...
A97[1, 2, 3, 4, 0] Help on built-infunction sininmodule math: sin(…) sin(x) Return the sine of x (measuredinradians). None [1, 2, 3, 4, 0] {0,1, 2, 3, 4} (1, 2, 3, 4, 0) 8.对象的删除(好习惯) x=[1,2,3,4,5] ...