Understanding class instantiation

wxPython Users
1

While I thought I understood class instatiation with wxPython I've
discovered that I still lack complete understanding. I've read the Python3
doc, Chapter 9 (Classes), Sections 9.3.3--9.3.5 and cannot find my error. I
want to learn to properly initialize and instantiate wxPython4 classes so
pointers to other references will be appreciated.

   The current issue is adding panels to a notebook. Both the wx.Frame and
wx.Notebook are in the same module and the notebook panels are imported at
the top of this module; e.g.,

   from sitePage import SiteGrid

and the notebook class is attached to the frame at the end of the wx.Frame
class:

         # Attach notebook
         self.theNB = MainNB(self, id=wx.ID_ANY)

   The notebook class:

class MainNB(wx.Notebook):
     def __init__(self, parent, id):
         wx.Notebook.__init__(self, parent, id, style=wx.NB_TOP)

         self.panel1 = SiteGrid(self,wx.ID_ANY)
   # plus the other panels.

         self.AddPage(self.panel1, "Sites")
   # plus the other panels.

   When I run the main module there's a type error:

$ ./openEDMS.py Traceback (most recent call last):
   File "./openEDMS.py", line 320, in <module>
     top = MainFrame(None, 'openEDMS')
   File "./openEDMS.py", line 161, in __init__
     self.theNB = MainNB(self, id=wx.ID_ANY)
   File "./openEDMS.py", line 283, in __init__
     self.panel1 = SiteGrid(self,wx.ID_ANY)
TypeError: __init__() takes 1 positional argument but 3 were given

   My readings haven't shown me where this inconsistency arises and I do need
to learn how to avoid these TypeErrors in the future.

TIA,

Rich

2

        self.panel1 = SiteGrid(self,wx.ID_ANY)

...

$ ./openEDMS.py Traceback (most recent call last):
  File "./openEDMS.py", line 320, in <module>
    top = MainFrame(None, 'openEDMS')
  File "./openEDMS.py", line 161, in __init__
    self.theNB = MainNB(self, id=wx.ID_ANY)
  File "./openEDMS.py", line 283, in __init__
    self.panel1 = SiteGrid(self,wx.ID_ANY)
TypeError: __init__() takes 1 positional argument but 3 were given

SiteGrid wants 1 non-keyword argument but you hand it 3:

  self.panel1 = SiteGrid(self,wx.ID_ANY)

non-keyword args:

  #1: self, auto-added by Python, = class-of-SiteGrid
  #2: self, again, given by you, = likely the MainNB instance
  #3: wx.ID_ANY, = -1

Look at

  SiteGrid.__init__

which is where the problem occurs, as the traceback says.

Karsten

···

On Sun, Apr 29, 2018 at 11:04:21AM -0700, Rich Shepard wrote:
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3

Karsten,

   Thank you. These imported modules were generated by wxFormBuilder and I
assumed -- incorrectly -- they worked as provided.

   I referenced the wx.Panel inits from a project written a dozen years ago
and that syntax works:

     def __init__(self, parent, id):
         wx.Panel.__init__(self, parent, id)

         self.SetClientSize(wx.Size(800, 600))

         self.Fit()

Much appreciated,

Rich

···

On Sun, 29 Apr 2018, Karsten Hilbert wrote:

Look at
  SiteGrid.__init__
which is where the problem occurs, as the traceback says.

4

They do, as long as they are used the way they are defined.

There is no magic (except for the "self" auto-added by
Python).

Karsten

···

On Sun, Apr 29, 2018 at 12:51:46PM -0700, Rich Shepard wrote:

  SiteGrid.__init__

  Thank you. These imported modules were generated by wxFormBuilder and I
assumed -- incorrectly -- they worked as provided.

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