def find_substring_in(s, sub):""" 使用in关键字查找子字符串 """if sub in s:return Trueelse:return False# 定义一个字符串string = 'A New String Hello, World!'sub_string = "Hello"print('例1，源字符串为：', string, ' 待查找字符串为：', sub_string)print('子字符串是否包含：...
print( str.index('python') ) #ValueError: substring not found 1. 2. 3. 4. 5. 6. 7. 二、字符串替换 string1.replace(string2, [count]) 将str1中的str1替换成str2,,count可选,如果指定count,则不超过count次,如果不指定,表示全部替换,可以通过这个方法轻松去掉空格 ## replace()函数 print('=...
S.find(substring, [start [,end]]) #可指范围查找子串,返回索引值,否则返回-1 S.rfind(substring,[start [,end]]) #反向查找 S.index(substring,[start [,end]]) #同find,只是找不到产生ValueError异常 S.rindex(substring,[start [,end]])#同上反向查找 S.count(substring,[start [,end]]) #返回...
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 ...
substring="python"string="welcome to pythontip"print(substringinstring) 如果存在,则返回True,否则返回False。此处,输出为True。 如何检查子字符串是否存在-另一种方法 你也可以使用find()方法检查字符串中是否存在子字符串。 如下示例: substring="zz"string="hello world"print(string.find(substring)) ...
File "E:/备份文档与数据/pythonworkspace/string_test.py", line 23, in <module> print(str.index(str2)) #如果str2不在str中会报异常,其余用法跟find一样 ValueError: substring not found 4.将字符串切换成大小写 str='hEllo,World!' print(str.lower()) #转换成小写 ...
substring2 =string[:-3] print(substring2) # Print"The quick brown " 获取字符串中的一个字符 这个很简单,如果切片中没有:字符,只包含数字,它将返回该索引处的字符。 例子: string='0123456789' substring =string[4] print(substring) # Print "4" ...
if substring in string: print('Found the substring!') else: print('Could not find the substring.') 使用index() 方法 Python String类有一个 index() 方法,如果在字符串中找到目标子字符串,它将返回子字符串的索引。当你需要知道子字符串的位置时,这很有用。以下是如何使用此方法的示例: ...
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 searched. find() Return Value Thefind()method returns an integer value: ...
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....