python insert
list.insert()方法 (list.insert() Method)
insert() is an inbuilt method in python, which is used to add an element /item at specified index to the list.
insert()是python中的内置方法，用于将指定索引处的元素/ item添加到列表中。
insert() is able to add the element where we want i.e. position in the list, which we was not able to do the same in list.append() Method.
insert()能够将元素添加到我们想要的位置，即列表中的位置，而list.append()方法无法做到这一点 。
Syntax:
句法：
list.insert(index, element)
Here,
这里，
list is the name of the list.
list是列表的名称。
index is the valid value of the position/index.
index是头寸/索引的有效值。
element is an item/element to be inserted.
元素是要插入的项目/元素。
Return type: Method insert() does not return any value, it just modifies the existing list.
返回类型：方法insert()不返回任何值，它仅修改现有列表。
Program:
程序：
# Python program to demonstrate
# an example of list.insert() method
# list
cities = ['New Delhi', 'Mumbai']
# print the list
print "cities are: ",cities
# insert 'Bangalore' at 0th index
index = 0
cities.insert(index,'Bangalore')
# insert 'Chennai' at 2nd index
index = 2
cities.insert(index, 'Chennai')
# print the updated list
print "cities are: ",cities
Output
输出量
cities are: ['New Delhi', 'Mumbai']cities are: ['Bangalore', 'New Delhi', 'Chennai', 'Mumbai']
Explanation:
说明：
Initially there were two elements in the list ['New Delhi', 'Mumbai'].
最初，列表中有两个元素['New Delhi'，'Mumbai'] 。
Then, we added two more city names (two more elements) - 1) 'Bangalore' at 0th index and 2) 'Chennai' at 2nd index after adding 'Bangalore' at 0th index, by using following python statements:
：在0在第二索引处0添加“班加罗尔” 个索引，通过使用以下Python语句后1)“班加罗尔” 个索引和2)“奈” -然后，我们增加了两个城市名称(两个元件)
# insert 'Bangalore' at 0th index
index = 0
cities.insert(index, 'Bangalore')
# insert 'Chennai' at 2nd index
index = 2
cities.insert(index, 'Chennai')
After inserting 'Bangalore' at 0th index, the list will be ['Bangalore', 'New Delhi', 'Chennai'].
在第 0 个索引处插入“班加罗尔”后，列表将为['Bangalore'，'New Delhi'，'Chennai'] 。
And, then we added 'Chennai' at 2nd index. After inserting 'Chennai' at 2nd index. The list will be ['Bangalore', New Delhi', 'Chennai', 'Mumbai'].
然后，我们在第二个索引处添加了“ Chennai” 。 在第二个索引处插入“ Chennai”之后。 该列表将是['Bangalore'，New Delhi'，'Chennai'，'Mumbai'] 。
So, it is at our hand, what we have to do? If our requirement is to add an element at the end of the list - use list.append() Method, or if our requirement is to add an element at any index (any specified position) - use list.insert() Method.
那么，这在我们眼前，我们该怎么办？ 如果我们的要求是在列表的末尾添加一个元素-使用list.append()方法 ，或者我们的要求是在任何索引(任何指定位置)添加一个元素-使用list.insert()方法。
翻译自: https://www.includehelp.com/python/list-insert-method-with-example.aspx
python insert
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