与find()方法不同的是,index()方法在找不到子字符串时会抛出ValueError异常,因此需要进行异常处理。 AI检测代码解析 deffind_all_positions(string,substring):positions=[]start=0try:whileTrue:position=string.index(substring,start)positions.append(position)start=position+1exceptValueError:passreturnpositions strin...
方法一:使用内置函数find()或rfind() 内置函数find()可以返回字符串中指定子字符串的第一个匹配位置,如果没有找到则返回 -1;而rfind()则返回最后一个匹配位置。 下面是使用find()和rfind()的代码示例: AI检测代码解析 # 寻找字符串首次出现的位置string="Hello, world!"substring="llo"index=string.find(subst...
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 this case it’s a conditional that can be eithertrueorfalse.It’ll be true if the substring is part of the ...
def find(self, sub, start=None, end=None): # real signature unknown; restored from __doc__ """ S.find(sub[, start[, end]]) -> int Return the lowest index in S where substring sub is found, such that sub is contained within S[start:end]. Optional arguments start and end are ...
Find all indexes of substring There is no built-in function to get the list of all the indexes for the substring. However, we can easily define one using find() function. def find_all_indexes(input_str, substring): l2 = [] length = len(input_str) ...
string='All around the world' substring =string[4:10] print(substring) # Print "around" 使用负索引对字符串进行切片 如果你不知道这个字符串的长度,你想获取最后一个字符改如何处理呢?方法一,是先获取字符串长度,然后取最后一个值:string[len(string) - 1]方法二,是使用负索引:string[-1]很明显,使用...
In another way, a substring can be defined as a part or subset of a string. Any modification in text data of a string is a part of the substring process. For example:“This is great work. We must pursue it.” is a type of string, and part of the string “We must pursue it” ...
find() Syntax The syntax of thefind()method is: str.find(sub[, start[, end]] ) find() Parameters Thefind()method takes maximum of three parameters: sub- It is the substring to be searched in thestrstring. startandend(optional) - The rangestr[start:end]within which substring is searche...
#defining string and substring str1 = "This dress looks good; you have good taste in clothes."...
.format(name, age)) # 使用f-string格式化 print(f"{name} is {age} years old.") 2.1.3 切片与索引操作 Python字符串支持切片操作,类似于列表,可以通过索引来访问和截取子字符串: string = "Python Programming" substring = string[7:14] # 从索引7开始至索引14前结束 print(substring) # 输出:"...