for num in L1: last_found = L2.index(num, last_found + 1) return True except ValueError: return False 1. 2. 3. 4. 5. 6. 列表L2的索引方法返回列表中第一个参数(num)的位置;像这里一样,用第二个arg调用,它开始查看该位置的列表.如果索引找不到它要查找的内容,则会引发ValueError异常. 因此...
Learn with the help of examples. By Sapna Deraje Radhakrishna Last updated : June 26, 2023 Given a Python list and an item, we have to find the index of the given item in the list. Consider the below example with sample input/output to understand the task better -...
>>> [1, 1].index(2) Traceback (most recent call last): File "<stdin>", line 1, in <module> ValueError: 2 is not in list If this is a concern, either explicitly check first using item in my_list, or handle the exception with try/except as appropriate. The explicit check is ...
在上面的示例中,我们创建了一个包含多个元素的列表list1,并使用lastindex方法来查找元素2的最后出现位置。由于2最后一次出现在索引5处,因此输出结果为5。 需要注意的是,如果要查找的元素在字符串或列表中不存在,lastindex方法将抛出ValueError异常。在使用lastindex方法时,我们可以使用try-except语句来捕获该异常并进行...
dataframe_object.index returns the list of all the index, to get any range of index you can use the list properties. To get the last element index: dataframe_object.index[-1] To get the First element index: dataframe_object.index[0] To get the index of first x elements index: data...
Enumerate()函数是python可用的内置函数。 您可以使用枚举来获取列表中元素的所有索引。 它以输入作为可迭代对象(即,可以循环的对象),而输出是带有每个项目计数器的对象。 下面的示例演示如何利用列表上的枚举来获取给定元素的所有索引。 my_list = ['Guru', 'Siya', 'Tiya', 'Guru', 'Daksh', 'Riya', 'Gu...
Finding first and last index of some value in a list in Python first index: verts.index(value) last index: len(verts)-1-verts[::-1].index(value)
list.index( )获得值的索引值,但是如果list中含有的值一样,例如含有两个11,22,这样每次获得的都是第一个值的位置。 那么怎么去解决这个问题呢? 下面的程序对这个问题做了一定的解答 #!/usr/bin/env python # -*- coding: utf-8 -*- # @Author : SundayCoder-俊勇 # @File : listlearn.py # 怎么...
{// here List<T> contains the object "gfg" using// data from a sample XML file// List initializeprivatestaticList<gfg> geeks =newList<gfg>();publicstaticvoidMain(){// if the item is found then// it prints the index// if not found prints "-1"intx = geeks.FindLastIndex(3, ...
are numbers from 0 to the list’s length. It is important to emphasize that the indexing begins from 0 and not one. This means that the first element has an index of 0. Following that pattern, the last element has an index of n-1 where n is the number of elements in the list. ...