substring：要查找的子字符串。start（可选）：开始查找的起始位置，默认为 0。end（可选）：结束查找的位置，默认为字符串的长度。示例：1. 查找子字符串：text = "Hello, world! This is an example."# 使用 find 查找子字符串index = text.find("world")print("Index of 'world':", index) # 输出...
AI检测代码解析 defindex_of_substring(string,substring):string_list=list(string)forindex,charinenumerate(string_list):ifchar==substring[0]:# 判断当前字符是否与子字符串的第一个字符相同ifstring[index:index+len(substring)]==substring:# 判断当前字符后续字符是否与子字符串匹配returnindexreturn-1 1. 2....
deffind_substrings(string,substrings):positions=[]forsubstringinsubstrings:index=string.find(substring)positions.append(index)returnpositions# 示例用法string="This is a test string."substrings=["is","test","string"]positions=find_substrings(string,substrings)print(positions)# 输出:[2, 10, 17] ...
我们可以先看一个简单的例子: s ="Duan Yixuan"x=len(s)print('The Length of %s is %d'%(s,x))#输出结果:The Length of Duan Yixuan is 11 分析: 'The length of %s is %d'这部分叫做:格式控制符 (s,x)这部分叫做:转换说明符 %字符,表示标记转换说明符的开始,类似于C语言中的用的逗号 接下来...
The index method can’t return a number because the substring isn’t there, so we get a value error instead: In order to avoid thisTraceback Error, we can use the keywordinto check if a substring is contained in a string. In the case of Loops, it was used for iteration, whereas in...
# find the index of isresult = text.index('is') print(result)# Output: 7 index() Syntax It's syntax is: str.index(sub[, start[, end]] ) index() Parameters Theindex()method takes three parameters: sub- substring to be searched in the stringstr. ...
find('or', 9)) # -1 print(s.find('of')) # -1 print(s.index('or')) # 8 print(s.index('or', 9)) # ValueError: substring not found 说明:find方法找不到指定的字符串会返回-1,index方法找不到指定的字符串会引发ValueError错误。 find和index方法还有逆向查找(从后向前查找)的版本,分别...
Python String find() The find() method returns the lowest index of the substring if it is found in given string. If its is not found then it returns -1. Syntax : str.find(sub,start,end) Parameters : sub :It’s the substring which needs to be searched in the given string....
in <module>ValueError: substring not found从Python手册string.find(s, sub[, start[, end]])返回s...
find() Return Value Thefind()method returns an integer value: If the substring exists inside the string, it returns the index of the first occurence of the substring. If a substring doesn't exist inside the string, it returns-1. Working of find() method ...