find方法返回的是子串出现的首位置。比如下面的这个,返回的是abc在str中的首位置也就是3。如果没找到将会返回-1 str = "dkjabcfkdfjkd198983abcdeefg" print str.find('abc') 1. 2. 但是在str中有2个abc,那么如何去查找到第二个abc的位置呢。由于find是会返回查找到的字符串的首位置,因此我们可以利用这个...
To achieve our goal, we’ll use theindexmethod which is a function associated with a specific class and serves for a certain function when attached to a variable following a dot. Theindexmethod in particular, returns the index of the given substring, inside the string.The substring that we ...
return s.find(*args) # Find last substring, return -1 if not found def rfind(s, *args): """rfind(s, sub [,start [,end]]) -> int Return the highest index in s where substring sub is found, such that sub is contained within s[start,end]. Optional arguments start and end are ...
def extract_substring(string, start, end): # 使用切片操作提取子字符串 substring = string[start:end] return substring def extract_substring_with_find(string, substring): # 使用find()方法查找子字符串的位置 start = string.find(substring) if start == -1: return None end = start + len(substr...
str.find() 查找 代码语言:javascript 代码运行次数:0 运行 AI代码解释 In [90]: help(s1.find) Help on built-in function find: find(...) 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]...
Find a Substring in a pandas DataFrame Column If you work with data that doesn’t come from a plain text file or from user input, but from aCSV fileor anExcel sheet, then you could use the same approach as discussed above. However, there’s a better way to identify which cells in ...
find("n", 5, 13)) print(str.index("abc")) print(str.index("n", 5, 13)) 执行以上代码,输出结果为: Traceback (most recent call last): File ".py", line 6, in <module> print(str.index("n", 5, 13)) ^^^ ValueError: substring not found 0 11 -1 0 (2)检索字符串包含目标字...
def index(self, sub, start=None, end=None): # real signature unknown; restored from __doc__ (和find差不多) """ S.index(sub[, start[, end]]) -> int Return the lowest index in S where substring sub is found, (返回找到提交字符串子字符串的最低索引,这样的子被包含在S[start.end]...
在您的 Python 生涯中,有一些基本的字符串操作您可能会用到很多次,比如len(字符串的长度)、连接、迭代、索引和切片(Python 的 substring 操作的等价物)。举例来说,在空闲会话中键入以下代码,注意结果与您在这里看到的输出相匹配:>>> len('shrubbery') 9 'shrubbery' is 9 characters long. >>> 'spam' +...
find('s')) # 8 str.index(a): 查找指定值的首次出现。如果找不到该值,index() 方法将引发异常。 print(s.index('s')) # 8 print(s.index('a')) # Traceback (most recent call last): # File "<stdin>", line 1, in <module> # ValueError: substring not found str.count(a): 统计...