[Python] str.startswith() 方法

谁借莪１个温暖的怀抱￠ 2021-10-19 10:18 303阅读 0赞

语法参考菜鸟教程：[https://www.runoob.com/python3/python3-string-startswith.html][https_www.runoob.com_python3_python3-string-startswith.html]

python2.7 和 python3.x均适用

[root@xxx ~]# python
    Python 2.7.6 (default, Feb 13 2017, 15:29:20)
    [GCC 4.4.7 20120313 (Red Hat 4.4.7-11)] on linux2
    Type "help", "copyright", "credits" or "license" for more information.
    >>> str = "this is string example....wow!!!"
    >>> print (str.startswith( 'this' ))
    True
    >>> print (str.startswith( 'string', 8 ))
    True
    >>> print (str.startswith( 'this', 5, 7))
    False
    >>> print (str.startswith( 'is', 5, 8))
    True
    >>>

应用举例：可以根据接收的命令，执行对应的方法。下例中，cmdline 是接受收的命令、是一个字符串

class bookManager():
    
        def __init__(self, cmdline, xmlPath):
            self.cmdline = cmdline
            self.xmlPath = xmlPath
            self.exeCmd()
    
        def exeCmd(self):
                if(self.cmdline.startswith('shelf_book add')):
                    self.addBook()
                elif(self.cmdline.startswith('shelf_book remove')):
                    self.removeBook()
                elif(self.cmdline.startswith('shelf_book modify')):
                    self.modifyBook()
    
        def addBook(self):
            pass
    
        def removeBook(self):
            pass
    
        def modifyBook(self):
            pass

友情方法，endswith()  语法参考菜鸟教程 [https://www.runoob.com/python3/python3-string-endswith.html][https_www.runoob.com_python3_python3-string-endswith.html]

python2.7 和 python3.x均适用

>>> print (str.endswith('!!'))
    True
    >>> print (str.endswith('wow', -6))
    False
    >>> print (str.endswith('wow!!!', -6))
    True
    >>> print (str.endswith('example', 12, 21))
    False
    >>> print (str.endswith('example', 12, 22))
    True
    >>>

应用举例：根据文件扩展名判断文件类型

[https_www.runoob.com_python3_python3-string-startswith.html]: https://www.runoob.com/python3/python3-string-startswith.html
[https_www.runoob.com_python3_python3-string-endswith.html]: https://www.runoob.com/python3/python3-string-endswith.html