["foo","bar","baz"].index("bar")
Python中是有查找功能的,五种方式:in、not in、count、index,find 前两种方法是保留字,后两种方式是列表的方法。 下面以a_list = ['a','b','c','hello'],为例作介绍: string类型的话可用find方法去查找字符串位置: a_list.find('a') 1. 如果找到则返回第一个匹配的位置,如果没找到则返回-1,而如果...
方法一:使用列表的index()方法 列表是Python中常用的数据结构之一,可以使用index()方法来查找元素在列表中的索引值。 deffind_index_in_list(lst,value):try:index=lst.index(value)returnindexexceptValueError:return-1# 示例my_list=[1,2,3,4,5]value=4index=find_index_in_list(my_list,value)print(f"...
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. Here’s an example of how to use theindex()method to find the index of the...
In this last example, we will use the index() method to get the search string in the list:try: my_list.index(search_string) print(True) except ValueError: print(False) # TrueThis example attempts to find the index of search_string within my_list using the index() method. The try ...
2)index string.index(str, beg=0, end=len(string))跟find()方法一样,只不过如果str不在 string中会报一个异常. 代码语言:javascript 代码运行次数:0 运行 AI代码解释 >>>mystr.index("how")12>>>mystr.index("how",20,30)Traceback(most recent call last):File"<stdin>",line1,in<module>ValueE...
可以看到,在查看器中选择一定的HTML代码区域,页面中也会有相应的高亮显示,说明需要获取的数据也就在这些对应的HTML代码中; 每一条结果的位置为class为job-list的div下面的ul下面的li下面的class为job-primary的div,有多少条职位信息就有多少个li,其中一个li的内容如下: 代码语言:javascript 代码运行次数:0 运行 ...
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 ...
5}# 删除键值对value=my_dict.pop('b')print(value)# 输出: 2print(my_dict)# 输出: {'a': 1, 'c': 3, 'd': 4, 'e': 5}# 获取值,如果不存在则返回默认值value=my_dict.get('f','Not Found')print(value)# 输出: Not Found# 检查键是否存在if 'a' in my_dict:print('Key exists...
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...