print str[:-3] #截取从头开始到倒数第三个字符之前 print str[2] #截取第三个字符 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...
复制 string模块,还提供了很多方法,如S.find(substring,[start[,end]])#可指范围查找子串,返回索引值,否则返回-1S.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[,...
方法四:使用str.find()和循环 除了上述方法,我们还可以使用str.find()方法和循环来查找字符串在字符串中的位置。下面是一个示例代码: text="Python is a powerful programming language"sub_string="p"index=-1whileTrue:index=text.find(sub_string,index+1)ifindex==-1:breakprint(f"The substring '{sub_...
ValueError: substring not fou 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16、rindex() 描述:rindex() 方法返回子字符串最后一次出现在字符串中的索引位置,该方法与 rfind() 方法一样,可以规定字符串的索引查找范围[star,end),只不过如果子字符串不在字符串中会报一个异常。 语...
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...
subString: vectorAcad Explanation: Firstly, an original string is created. Then, a slicing operator is used in which the endIndex syntax is passed. In the final output, we find that a substring is generated which starts from the beginning of the string and ends at the position where endInde...
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 ...
find() 方法: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 interpreted as in slice notation.
2. Substring or slicing 通过使用slice语法,我们可以获得一系列字符。索引从零开始。 str[m:n] 从位置2(包括)到5(不包括)返回字符串。 从索引2到5的子字符串 str = 'hello world' print(str[2:5]) # llo 负切片将从末尾返回子字符串。 子串从索引-5到-2 ...
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 ...