[Tutor] global variables/constants versus volatile variables/constants

[diliup gabadamudalige]

Thank you all for those great clarifications. I learnt a lot from these.
My roots in programming are from the early 80s and with a gap of nearly 30
years till I restarted again last year in March with Python. :) So some of
the new concepts like classes are a bit alien to me but I am catching on.
I made a mistake by using the word variables on variables and constants
both. My design structure would most probably be quite unconventional to
most like Allen Gauld says. I am still learning and I like to jump into the
deep end and learn to swim there and so far have managed to stay alive! :)
I have gained immensely from these few emails and hope I can gain more
knowledge to write better code.

Say if I have a lot of Lists, strings and variables used to carry data to
and from various functions why can't I have a class with all these in it? I
thought on the lines of blood carrying various things to different organs
in the body. One common container class. Containers for data exchange
between all classes and functions.
so I declare

class Containers():
    def __init__(self):
self.last_selected_scale= ""
self.scale_notes = ""
self.arpeggionotes = ""
self.handplayed_notes = []
self.MIDIscale = []  # the MIDI scale to be played is here
self.play_MIDIscale = False
self.play_MIDIarpeggio = False
self.play_MIDI_scale_note = False
self.play_MIDI_arpeggio_note = False
self.MIDInote_inscale = 0

now i initiate the class with
v=Containers()

now say if I play the MIDI keyboard, I collect the notes played which will
be appended to the list v.hanplayednotes. This will be done from a function
which will scan the keyboard and append played notes to that list.

This is how I have used these variables, lists and strings in this program.
So far it has run error free.

Is this not correct or bad design. I know it is not the normal way of using
class but is it wrong?

Thank you all in advance.


-- 
Diliup Gabadamudalige

http://www.diliupg.com
http://soft.diliupg.com/

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