1#!/usr/bin/env python 2 3# portable serial port access with python 4# this is a wrapper module for different platform implementations 5# 6# (C) 2001-2010 Chris Liechti <cliechti@gmx.net> 7# this is distributed under a free software license, see license.txt 8 9VERSION = '2.7' 10 11import sys 12 13if sys.platform == 'cli': 14 from serial.serialcli import * 15else: 16 import os 17 # chose an implementation, depending on os 18 if os.name == 'nt': #sys.platform == 'win32': 19 from serial.serialwin32 import * 20 elif os.name == 'posix': 21 from serial.serialposix import * 22 elif os.name == 'java': 23 from serial.serialjava import * 24 else: 25 raise ImportError("Sorry: no implementation for your platform ('%s') available" % (os.name,)) 26 27 28protocol_handler_packages = [ 29 'serial.urlhandler', 30 ] 31 32def serial_for_url(url, *args, **kwargs): 33 """\ 34 Get an instance of the Serial class, depending on port/url. The port is not 35 opened when the keyword parameter 'do_not_open' is true, by default it 36 is. All other parameters are directly passed to the __init__ method when 37 the port is instantiated. 38 39 The list of package names that is searched for protocol handlers is kept in 40 ``protocol_handler_packages``. 41 42 e.g. we want to support a URL ``foobar://``. A module 43 ``my_handlers.protocol_foobar`` is provided by the user. Then 44 ``protocol_handler_packages.append("my_handlers")`` would extend the search 45 path so that ``serial_for_url("foobar://"))`` would work. 46 """ 47 # check remove extra parameter to not confuse the Serial class 48 do_open = 'do_not_open' not in kwargs or not kwargs['do_not_open'] 49 if 'do_not_open' in kwargs: del kwargs['do_not_open'] 50 # the default is to use the native version 51 klass = Serial # 'native' implementation 52 # check port type and get class 53 try: 54 url_nocase = url.lower() 55 except AttributeError: 56 # it's not a string, use default 57 pass 58 else: 59 if '://' in url_nocase: 60 protocol = url_nocase.split('://', 1)[0] 61 for package_name in protocol_handler_packages: 62 module_name = '%s.protocol_%s' % (package_name, protocol,) 63 try: 64 handler_module = __import__(module_name) 65 except ImportError: 66 pass 67 else: 68 klass = sys.modules[module_name].Serial 69 break 70 else: 71 raise ValueError('invalid URL, protocol %r not known' % (protocol,)) 72 else: 73 klass = Serial # 'native' implementation 74 # instantiate and open when desired 75 instance = klass(None, *args, **kwargs) 76 instance.port = url 77 if do_open: 78 instance.open() 79 return instance 80