SyntaxError：将字串转换为int后，语法无效

Question

I have written a piece of code in python and when I let it run I get the following message:

File "port.py", line 229
    port = (int) a
                 ^
SyntaxError: invalid syntax

since the code is a little bit too long, I give only the important part in the following section:

try:
        opts, args = getopt.getopt(sys.argv[1:], 'hle:t:p:cu:',
                                   ['help','listen','execute', 'target',
                                    'port', 'command', 'upload'])
    except getopt.GetoptError as err:
        print(str(err))
        usage()

    for o,a in opts:
        if o in ('-h', '--help'):
            usage()
        elif o in ('-l','--listen'):
            listen = True
        elif o in ('-e', '--execute'):
            execute = a
        elif o in ('-c','--commandshell'):
            command = True
        elif o in ('-u','--upload'):
            upload_destination = a
        elif o in ('-t','--target'):
            target = a
        elif o in ('-p','--port'):
            port = (int) a
        else:
            assert False,'Unhandled Option'

So, the a should be the port number which has string as type. So, I thought that I should cast it.

The version of python is 2.7.3.

I could not figure out why the error message appears. I hope somebody can help.

Best regards,

Answer 1

要从字符串a创建一个新的int对象，请使用

port = int(a)