importre string="Hello, World!"substring=re.findall(r", (.*?)!",string)[0]# 使用正则表达式截取", "和"!"之间的字符串print(substring)# 输出 "World" 1. 2. 3. 4. 5. 在上面的例子中,使用正则表达式", (.*?)!"来匹配逗号和感叹号之间的字符串。findall方法返回一个列表,我们只取第一个...
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。 deffind_all_positions(string,substring):positions=[]start=0try:whileTrue:position=string.index(substring,start)positions.append(position)start=position+1exceptValueError:passreturnpositions string="Hello, Worl...
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. s = 'My Name is Pankaj' print('Substring count =', 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 Working of Python string's find()...
string is: This dress looks good; you have good taste in clothes. The substring to find: good...
print str[-1] #截取倒数第一个字符 print str[::-1] #创造一个与原字符串顺序相反的字符串 print str[-3:-1] #截取倒数第三位与倒数第一位之前的字符 print str[-3:] #截取倒数第三位到结尾 print str[:-5:-3] #逆序截取 输出结果如下: ...
.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:"...
顺便对比下re.match、re.search、re.findall的区别 match()函数只在string的开始位置匹配(例子如上图)。 search()会扫描整个string查找匹配,会扫描整个字符串并返回第一个成功的匹配。 re.findall()将返回一个所匹配的字符串的字符串列表。 ———分割线——— 《用python写网络爬虫》中1.4.4链接爬虫中,下图...
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...
How to Check if a Python String Contains a Substring In this quiz, you'll check your understanding of the best way to check whether a Python string contains a substring. You'll also revisit idiomatic ways to inspect the substring further, match substrings with conditions using regular expressio...