Python Code: # Define a function 'find_index_of_all' that takes a list 'lst' and a function 'fn' as input.deffind_index_of_all(lst,fn):# Use a list comprehension to find and collect the indices 'i' where 'fn(x)' is True for an element 'x' in 'lst'.return[ifori,xinenumera...
这段代码会输出The index of 3 in the list is: 2,因为3在列表中的索引位置是2。 使用enumerate()方法 除了index()方法外,我们还可以使用enumerate()方法来查找元素在列表中的位置。下面是一个使用enumerate()方法的示例: arr=[1,2,3,4,5]target=3forindex,valueinenumerate(arr):ifvalue==target:print(...
2. list.index() – Multiple occurrences of element in the list When the element, whose index we are trying to find, occurs multiple times in the list,index()method returns the index of first match and ignores the other occurrences. In the following program, we take a list where element'...
# 示例数组my_list=[10,20,30,20,40,20]# 要查找的元素element_to_find=20# 获取所有 20 的索引indexes=[indexforindex,valueinenumerate(my_list)ifvalue==element_to_find]print(f"元素{element_to_find}的所有索引为:{indexes}") 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 输出结果 元素20 的所...
my_list = [1, 2, 3, 4, 5] element = 3 index = my_list.index(element) print("元素", element, "的索引是", index) 输出结果为: 代码语言:txt 复制 元素3 的索引是 2 如果要查找的元素不在列表中,index()方法会抛出ValueError异常。为了避免异常的发生,可以使用in关键字来判断元素是否在列表中...
This article mainly introduces how to find the position of an element in a list using Python, which is of great reference value and hopefully helpful to everyone. How to Find the Position of an Element in a List Problem Description Given a sequence containing n integers, determine the ...
Theindex()method returns the index of the given element in the list. If the element is not found, aValueErrorexception is raised. Note: Theindex()method only returns the first occurrence of the matching element. Example 1: Find the index of the element ...
2. Using theindex()Method (For Finding the First Occurrence) Theindex()method is used to find the index of the first occurrence of a specified element in a list. This method is particularly useful when you need to know the position of a specific element within a list. ...
Return Value from List index() The index() method returns the index of the given element in the list. If the element is not found, a ValueError exception is raised. Note: The index() method only returns the first occurrence of the matching element. Example 1: Find the index of the ele...
If the value is not found in the sequence, the function raises a ValueError. For example, if we have a list[1, 2, 3, 4, 5], we can find the index of the value3by callinglist.index(3), which will return the value2(since3is the third element in the list, and indexing starts ...