No macros in Python

[Mel Wilson]

In article <Pine.GSO.4.44_heb2.09.0212160242440.16160-100000 at techunix.technion.ac.il>,
Beni Cherniavsky <cben at techunix.technion.ac.il> wrote:
>On 2002-12-15, Mel Wilson wrote:
>
>>  If you must have such a thing as C macros, it's
>> available.I tried this as a way of simplifying the
>> creation of a lot of edit boxes with wxPython:
>>
>> new_edit_box_macro = """\
>> hs = wxBoxSizer (wxHORIZONTAL)
>> hs.Add (wxStaticText (self, -1, '%(label)s', wxDefaultPosition, labelsize)
>> self.%(field)s_ctrl = wxTextCtrl (self, -1, '', wxDefaultPosition)
                 ^
   later..
>> hs.Add (self, %(field)s_ctrl, 1)
>> vs.Add (hs, 0, wxGROW)"""
>>
>> exec (new_edit_box_macro % {'label':'Key No.', 'field':'person_id'})
>> exec (new_edit_box_macro % {'label':'First Name', 'field':'fname'})
>> exec (new_edit_box_macro % {'label':'Last Name', 'field':'lname'})
>>
>> and so on.
>>
># Untested
>for label, field in [('Key No.', 'person_id'),
>                     ('First Name', 'fname'),
>                     ('Last Name', 'lname')]:
>    hs = wxBoxSizer (wxHORIZONTAL)
>    hs.Add (wxStaticText (self, -1, label, wxDefaultPosition,
>                          labelsize))
>    ctrl = wxTextCtrl (self, -1, '', wxDefaultPosition)

     ^
   The original named this `person_id_ctrl`, etc.  The
original made this detail hard to spot.  Could of course be
fixed in the `for` list.  C macros in actual C have quite
a tough time with string splicing like this.

>    hs.Add (self, ctrl, 1)
>    vs.Add (hs, 0, wxGROW)
>    self.__dict__[field + '_ctrl'] = ctrl
>
>Variable assignment is not the real point of macros IMHO.

   True.  Creating source code from other strings is the real
point of C macros.

   My comeuppance will be when this gets converted to Visual
Basic per customer spec.  All that ersatz macro stuff will
have to be taken down.

        Regards.        Mel.