如何在Python中声明和添加项目到数组?
本文翻译自:How to declare and add items to an array in Python?
I'm trying to add items to an array in python. 我试图将项目添加到python中的数组。
I run 我跑
array = {}
Then, I try to add something to this array by doing: 然后,我尝试通过以下操作向此数组添加一些内容:
array.append(valueToBeInserted)
There doesn't seem to be a .append
method for this. 似乎没有.append
方法。 How do I add items to an array? 如何将项目添加到数组?
#1楼
参考:https://stackoom.com/question/i0De/如何在Python中声明和添加项目到数组
#2楼
No, if you do: 不,如果您这样做:
array = {}
IN your example you are using array
as a dictionary, not an array. 在您的示例中,您使用array
作为字典,而不是数组。 If you need an array, in Python you use lists: 如果需要数组,则在Python中使用列表:
array = []
Then, to add items you do: 然后,要添加项目,请执行以下操作:
array.append('a')
#3楼
{}
represents an empty dictionary, not an array/list. {}
代表空字典,而不是数组/列表。 For lists or arrays, you need []
. 对于列表或数组,您需要[]
。
To initialize an empty list do this: 要初始化一个空列表,请执行以下操作:
my_list = []
or 要么
my_list = list()
To add elements to the list, use append
要将元素添加到列表,请使用append
my_list.append(12)
To extend
the list to include the elements from another list use extend
要extend
列表以包括另一个列表中的元素,请使用extend
my_list.extend([1,2,3,4])
my_list
--> [12,1,2,3,4]
To remove an element from a list use remove
要从列表中remove
元素,请使用remove
my_list.remove(2)
Dictionaries represent a collection of key/value pairs also known as an associative array or a map. 字典表示键/值对的集合,也称为关联数组或映射。
To initialize an empty dictionary use {}
or dict()
要初始化一个空字典,请使用{}
或dict()
Dictionaries have keys and values 字典具有键和值
my_dict = {'key':'value', 'another_key' : 0}
To extend a dictionary with the contents of another dictionary you may use the update
method 要使用其他词典的内容扩展词典,可以使用update
方法
my_dict.update({'third_key' : 1})
To remove a value from a dictionary 从字典中删除值
del my_dict['key']
#4楼
Arrays (called list
in python) use the []
notation. 数组(在python中称为list
)使用[]
表示法。 {}
is for dict
(also called hash tables, associated arrays, etc in other languages) so you won't have 'append' for a dict. {}
用于dict
(在其他语言中也称为哈希表,关联的数组等),因此您无需为字典添加“追加”。
If you actually want an array (list), use: 如果您实际上想要一个数组(列表),请使用:
array = []
array.append(valueToBeInserted)
#5楼
In some languages like JAVA you define an array using curly braces as following but in python it has a different meaning: 在某些语言(例如JAVA)中,您可以使用花括号定义数组,如下所示,但在python中,它具有不同的含义:
Java: Java:
int[] myIntArray = {1,2,3};
String[] myStringArray = {"a","b","c"};
However, in Python, curly braces are used to define dictionaries, which needs a key:value
assignment as {'a':1, 'b':2}
但是,在Python中,花括号用于定义字典,该字典需要将key:value
分配为{'a':1, 'b':2}
To actually define an array (which is actually called list in python) you can do: 要实际定义一个数组(在python中实际上称为list),您可以执行以下操作:
Python: 蟒蛇:
mylist = [1,2,3]
or other examples like: 或其他示例,例如:
mylist = list()
mylist.append(1)
mylist.append(2)
mylist.append(3)
print(mylist)
>>> [1,2,3]
#6楼
I believe you are all wrong. 我相信你们都错了。 you need to do: 您需要执行以下操作:
array = array[]
in order to define it, and then: array = array[]
以便对其进行定义,然后:
array.append ["hello"]
to add to it. array.append ["hello"]
添加到它。