python 装饰器修改调整函数参数

简单记录一下利用python装饰器来调整函数的方法。现在有个需求：参数line范围为1-16，要求把9-16的范围转化为1-8，即9对应1,10对应2,...,16对应8。

下面是例子：

 def format_lines():
     def make_wrapper(func):
         def wrapper(*args, **kwargs):
             lines = list(args)[1:]
             new_args = list()
             for index, line in enumerate(lines):
                 if isinstance(line,tuple):
                     for index, l in enumerate(line):
                         if line > 8 and line <16 :
                             line = line % 8
                         elif line == 16:
                             line = 8
                         new_args.insert(index,line)
                     new_args.insert(0,args[0])
                     return func(*tuple(new_args), **kwargs)
                 else:
                     if line > 8 and line <16 :
                         line = line % 8
                     elif line == 16:
                         line = 8
                     new_args.insert(index,line)
             new_args.insert(0,args[0])
             return func(*tuple(new_args), **kwargs)
         return wrapper
     return make_wrapper

注意：wrapper的参数args即实际的lines，修改完后，传递给实际的func函数即可

使用：

class MainCom_Usb_Cmd():
    """atc platform hardware usb cmd

    """
    def __init__(self,ip,port):
        self.address = (ip, int(port))

    @format_lines()
    def turn_on_usb_signal(self,*lines):
        """only turn on usb signal

        """
        if not lines :
            lines = range(1,9)

        while True:
            try:
                self.client = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
                self.client.connect(self.address)
                break
            except Exception, e:
                time.sleep(0.1)
                continue
        try:
            is_succeed = True
            self.close_usb(lines,is_connect=True)
            for line in lines:
                retry_count = 0
                while retry_count < 3:
                    self.client.send('SwitchToUSB:::&%d&&&&\n\r' % line)
                    time.sleep(.2)
                    data = self.client.recv(1024)
                    if len(data)>0:
                        print data
                    pattern = re.compile(r"CH%d\s+USB\s+sig\s+connect\s+to\s+PCUSB" % line)
                    match = pattern.search(data)
                    if match is None:
                        retry_count = retry_count + 1
                    else:
                        break
                if retry_count >= 3:
                    is_succeed = False
        except:
            traceback.print_exc()
        finally:
            self.client.close()
            return is_succeed

    @format_lines()
    def turn_on_usb_power(self,*lines):
        """only turn on usb power for fastly charging device

        """  

        if not lines:
            lines = range(1,9)

        while True:
            try:
                self.client = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
                self.client.connect(self.address)
                break
            except Exception, e:
                time.sleep(0.1)
                continue
        try:
            is_succeed = True
            self.close_usb(lines,is_connect=True)
            for line in lines:
                retry_count = 0
                while retry_count < 3:
                    self.client.send('SwitchToDUT5V:::&%d&&&&\n\r' % line)
                    time.sleep(.2)
                    data = self.client.recv(1024)
                    if len(data)>0:
                        print data
                    pattern = re.compile(r"CH%d\s+USB\s+POWER\s+connect" % line)
                    match = pattern.search(data)
                    if match is None:
                        retry_count = retry_count + 1
                    else:
                        break
                if retry_count >= 3:
                    is_succeed = False
        except:
            traceback.print_exc()
        finally:
            self.client.close()
            return is_succeed