index() Return Value 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 that...
下面是一个更完整的示例,演示如何在一个长字符串中查找多个子字符串,并获取它们的位置。 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","strin...
--- IndexError Traceback (most recent call last) <ipython-input-70-e894f93573ea> in <module> ---> 1 word[42] # The word only has 6 characters. IndexError: string index out of range 但在范围内,太大的索引值会默认为字符串的大小,不会导致错误。 如果你总是希望在特定索引处开始切片...
Python是一门动态类型语言,和C、JAVA等语言不同,你无需手动指明变量的数据类型,根据赋值的不同你可以随意更改一个变量的数据类型,举例来说刚才我们把“整数”这个数据类型赋值给了a这个变量,现在我们再次赋值一个内容为test的"字符串"(String)数据类型给变量a,然后用type()函数来确认,这时你会发现a的数据类型已经...
list1[index] = 值 list4 = [22, 33, 12, 32, 45] list4[0] = "hello" print(list4[0]) 4.列表操作 4.1 列表组合 语法: 列表3 = 列表1 + 列表2 将列表1和列表2中的元素取出,组成一个新的列表并返回。 list1 = [1, 2, 3]
Python标准数据类型-String(字符串) ✨字符串简介 在Python程序中,字符串类型'str'是最常用的数据类型。 可以使用单引号''双引号""三引号'''来创建字符串。(单引号,双引号创建的字符串只能在一行,三引号创建的字符串可以分布在多行) 创建字符串的方法很简单,只需要为变量分配一个值即可 代码...
A string is printable if all of its characters are considered printable in repr() or if it is empty. """ pass def isspace(self, *args, **kwargs): # real signature unknown """ Return True if the string is a whitespace string, False otherwise. ...
importrestr="Hello, world!"char="o"pattern=re.compile(char)match=pattern.search(str)ifmatch:index=match.start()print(f"The index of{char}is{index}")else:print(f"Cannot find{char}in the string") 1. 2. 3. 4. 5. 6. 7.
1. Using theinOperator (Fastest for Membership Testing) Theinoperator is the most straightforward way to check if a string is present in a list. It is also the fastest method for membership testing, making it a great choice for simple checks. Here’s an example of how to use it: ...
20])IndexError: string index out of range>>> dict1={"name":"zhangsan","age":20}>>> print(dict1["year"])Traceback (most recent call last): File "<pyshell#10>", line 1, in <module> print(dict1["year"])KeyError: 'year'>>> n=123>>> n.lower()Traceback (most recent ...