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] ...
首先,我们需要定义一个名为String的类,该类将包含一个名为indexOf的方法。以下是实现的代码示例: classString:def__init__(self,value):self.value=valuedefindexOf(self,substring):returnself.value.find(substring) 1. 2. 3. 4. 5. 6. 在这个类中,我们首先定义了一个构造函数__init__,它接受一个字符...
If substring exists inside the string, it returns the lowest index in the string where substring is found. If substring doesn't exist inside the string, it raises aValueErrorexception. Theindex()method is similar to thefind()method for strings. The only difference is thatfind()method returns-...
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. start :...
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...
if s.find('Name') != -1: print('Substring found') Note that find() function returns the index position of the substring if it’s found, otherwise it returns -1. Count of Substring Occurrence We can usecount() functionto find the number of occurrences of a substring in the string. ...
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 ...
python 自带的两个查找字符串的方法:find 和rfind. Python String find() Method Description: This method determines ifstroccurs in string, or in a substring of string if starting indexbegand ending indexendare given. beg 和 end 可以缺省,这样find整个字符串 ...
in <module>ValueError: substring not found从Python手册string.find(s, sub[, start[, end]])返回s...
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...