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. 3. 4. 5. ...
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-...
find() function count() functionto find the number of occurrences of a substring in the string. s = 'My Name is Pankaj' print('Substring count =', s.count('a')) s = 'This Is The Best Theorem' print('Substring count =', s.count('Th')) Output: Find all indexes of substring Th...
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] ...
substring = 'Python' substring in string2 (4)索引(Indexing) 使用方括号和索引可以获取字符串中特定位置的字符。索引从 0 开始。 char_at_index_2 = string1[2] # 结果为 'l' (5)切片(Slicing) 使用方括号和切片语法可以获取字符串的子串。
Write a Python program to determine the index of a given string at which a certain substring starts. If the substring is not found in the given string return 'Not found'. Sample Solution: Python Code: # Function to find index of substringdeffind_Index(str1,pos):# Check if pos longer ...
comprehension + startswith() # All occurrences of substring in string res = [i for i in ...
Python supports both indexing, which extracts individual characters from a string, and slicing, which extracts a substring (or slice). To slice, you indicate a range in the format start:end. The start position is included in the returned substring, but the end position is excluded:Python Copy...
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...
python学习string method: find and rfind 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....