Python function calling

Question

I have the following classes:

from forwind.lidarapi.api import MCLidarGUIPlugin


class MCLidarActions( Handler ):

    tcp_send = Event

    def object__updated_changed( self, info ):
        print info;
        pass;   

    def _tcp_send_changed( self ):
        print( "Click" )

and

from forwind.lidarapi.actions.api import MCLidarActions

class MCUDPActions( MCLidarActions ):

    def object__updated_changed( self, info ):
        pass;   

    def _tcp_send_changed( self ):
        print( "Click UDP" )

When I click on a button in the MCLidarActions the _tcp_send_changed function will be called, how can I extend this function, I want to take action in the MCUDPActions as well. In this case If I click on the button it will printed out click but I want to print out Click UDP as well

Answer 1

If I understood correctly you problem, you could do:

class MCLidarActions( object ):
    li = []

    tcp_send = 'Event'

    def object__updated_changed( self, info ):
        print info;
        pass;

    def _tcp_send_changed( self ):
        print( "Click" )
        for x in self.li:
            x._tcp_send_changed()


class MCUDPActions( MCLidarActions ):
    def __init__(self):
        self.li.append(self)
    def object__updated_changed( self, info ):
        pass;
    def _tcp_send_changed( self ):
        print( "Click UDP" )


class MC_uuuuuuuuuuuuuutp_Actions( MCLidarActions ):
    def __init__(self):
        self.li.append(self)
    def object__updated_changed( self, info ):
        pass;
    def _tcp_send_changed( self ):
        print( "Click _uuuuuuuuuuuuuutp_" )



M = MCLidarActions()
print 'M, instance of MCLidarActions, created ------------'
print '  executing  M._tcp_send_changed():'
M._tcp_send_changed()


a = MCUDPActions()
print '\na, instance of MCUDPActions, created ------------'
print '  executing  M._tcp_send_changed():'
M._tcp_send_changed()
print
print '  executing  a._tcp_send_changed():'
a._tcp_send_changed()


b = MCUDPActions()
print '\nb, instance of MCUDPActions, created ------------'
print '  executing  M._tcp_send_changed():'
M._tcp_send_changed()
print
print '  executing  a._tcp_send_changed():'
a._tcp_send_changed()
print
print '  executing  b._tcp_send_changed():'
b._tcp_send_changed()


v = MC_uuuuuuuuuuuuuutp_Actions()
print '\nv, instance of MC_uuuuuuuuuuuuuutp_Actions, created ------------'
print '  executing  M._tcp_send_changed():'
M._tcp_send_changed()
print
print '  executing  a._tcp_send_changed():'
a._tcp_send_changed()
print
print '  executing  b._tcp_send_changed():'
b._tcp_send_changed()
print
print '  executing  v._tcp_send_changed():'
v._tcp_send_changed()

result

M, instance of MCLidarActions, created ------------
  executing  M._tcp_send_changed():
Click

a, instance of MCUDPActions, created ------------
  executing  M._tcp_send_changed():
Click
Click UDP

  executing  a._tcp_send_changed():
Click UDP

b, instance of MCUDPActions, created ------------
  executing  M._tcp_send_changed():
Click
Click UDP
Click UDP

  executing  a._tcp_send_changed():
Click UDP

  executing  b._tcp_send_changed():
Click UDP

v, instance of MC_uuuuuuuuuuuuuutp_Actions, created ------------
  executing  M._tcp_send_changed():
Click
Click UDP
Click UDP
Click _uuuuuuuuuuuuuutp_

  executing  a._tcp_send_changed():
Click UDP

  executing  b._tcp_send_changed():
Click UDP

  executing  v._tcp_send_changed():
Click _uuuuuuuuuuuuuutp_

But in the above code, it is necessary to define a function __init__ in each subclass MCUDPActions and MC_uuuuuuuuuuuuuutp_Actions of the base class MCLidarActions

To avoid that , the appending in li can be put in the base class:

class MCLidarActions( object ):
    li = []

    tcp_send = 'Event'

    def __init__(self):
        if self.__class__ != MCLidarActions:
            self.li.append(self)

    def object__updated_changed( self, info ):
        print info;
        pass;

    def _tcp_send_changed( self ):
        print( "Click" )
        for x in self.li:
            x._tcp_send_changed()




class MCUDPActions( MCLidarActions ):
    def object__updated_changed( self, info ):
        pass;
    def _tcp_send_changed( self ):
        print( "Click UDP" )


class MC_uuuuuuuuuuuuuutp_Actions( MCLidarActions ):
    def object__updated_changed( self, info ):
        pass;
    def _tcp_send_changed( self ):
        print( "Click _uuuuuuuuuuuuuutp_" )

and the result is exactly the same.

Answer 2

Here is the example of calling super() Beware that you need to inherit object inorder to make super works.

class E(object):
    def __init__(self):
        print "enter E"
        print "leave E"

class F(E):
    def __init__(self):
        print "enter F"
        super(F, self).__init__()
        print "leave F"

f = F()