Writing cleaner code

GaryN

I did post something similar recently but I think either I was very unclear or I was asking for too much or, possibly, maybe I was thought to being lazy.

Anyway, what I want to do, if possible, is learn to code using QT more effectively, more elegantly. I have the book, use this forum and the online resources but I still walk away with some confusions, or feelings that things could be better.

Let me explain; a section of my code is this...

import sys
import math
import numpy as np

import matplotlib
matplotlib.use('Qt5Agg')

from PyQt6.QtCore import Qt, QSize
from PyQt6.QtWidgets import (QApplication, QMainWindow, QWidget, QVBoxLayout)

from matplotlib.backends.backend_qt5agg import FigureCanvasQTAgg as FCQTA, NavigationToolbar2QT as NTbar
from matplotlib.figure import Figure


def convert(oldValue):
	---- SHOULD THIS FUNCTION BE MOVED TO INSIDE THE MAINWINDOW CLASS?
	
	return newValue


def readData(datafile):
	
	---- SHOULD THIS FUNCTION BE MOVED TO INSIDE THE MAINWINDOW CLASS?
	
	return data


class MplCanvas(FCQTA):
	
	def __init__(self, parent=None, width=5, height=4, dpi=100):
		
		fig = Figure(figsize=(width, height), dpi=dpi)
		self.axs = fig.add_subplot(111)																					
		super(MplCanvas, self).__init__(fig)


class MainWindow(QMainWindow):
	
	def __init__(self):
		
---------CODE HERE----------
		
		sc = MplCanvas(self, width=5, height=4, dpi=100)
		
		for index, filename in enumerate(filenames):
			stellarData = readData(filename)
			colour = colours[index % 7]
			line = lines[index // 7]

---------CODE HERE----------
		self.show()


if __name__ == "__main__":
 ---------CODE HERE----------

Since the two functions are only used within the mainWindow class, should I move those into there and, if so, how would I reference them in the code?

Then...

import sys
import math
import numpy as np

import matplotlib
matplotlib.use('Qt5Agg')

from PyQt6.QtCore import Qt, QSize
from PyQt6.QtWidgets import (
	QApplication,
	QMainWindow,
	QWidget,
	QVBoxLayout,
)

from matplotlib.backends.backend_qt5agg import FigureCanvasQTAgg as FCQTA, NavigationToolbar2QT as NTbar
from matplotlib.figure import Figure


def convert(oldValue):
       ---- SOME CODE HERE ----
	return newValue


def readData(datafile):
        ----SOME CODE HERE ----
	return data


class MplCanvas(FCQTA):
	def __init__(self, parent=None, width=5, height=4, dpi=100):
		fig = Figure(figsize=(width, height), dpi=dpi)
		self.axs = fig.add_subplot(111)																					
		super(MplCanvas, self).__init__(fig)


class MainWindow(QMainWindow):
	def __init__(self):
		super(MainWindow, self).__init__()
		
########## HERE 1 ########

		SIGMA = 5.67051e-5
		PI    = math.pi
		M_SUN = 1.989e33
		L_SUN = 3.826e33
		R_SUN = 6.9599e10
		YEAR  = 3.15570e7

		sa_sun = 4 * PI * math.pow(R_SUN, 2)
		t_sun  = L_SUN / (sa_sun * SIGMA)
		
		filenames = ["dummy0.5.lst", "dummy1.lst", "dummy2.lst", "dummy5.lst", "dummy10.lst", "dummy20.lst"]
		colours = ['r', 'g', 'b', 'c', 'm', 'y', 'k']
		lines = ['solid', 'dotted', 'dashed', 'dashdot']

########## END HERE 1 ########

		self.setWindowTitle("StelCor")
		self.setFixedSize(QSize(1024, 768))
		
		sc = MplCanvas(self, width=5, height=4, dpi=100)
		
		for index, filename in enumerate(filenames):
			stellarData = readData(filename)
			colour = colours[index % 7]
			line = lines[index // 7]

############## HERE 2 #############
		
			l_star = stellarData[:, 4] / L_SUN
			r_star = np.power(stellarData[:, 3] / R_SUN, 2)
			t_star = np.power((t_sun * l_star) / r_star, 0.25)

			sc.axs.loglog(t_star[:], l_star[:], color=colour, linestyle=line, label=filename)
	
			sc.axs.set_title(r'Temperature Magnitude (TM) Diagram')
			sc.axs.set_xlabel(r'Surface Temperature (Kelvin) - ${(\frac{t_{\odot} \times L_{\star}}{R_{\odot}})}^\frac{1}{4}$')
			sc.axs.set_ylabel(r'Luminosity (Solar Units) - $\frac{L_{\star}}{L_{\odot}}$')
			

############## END HERE 2 #############
			
		sc.axs.invert_xaxis()
		sc.axs.legend()
		
		tb = NTbar(sc, self)

		layout = QVBoxLayout()
		layout.addWidget(tb)
		layout.addWidget(sc)
		

############## OR END HERE 2 #############

		widget = QWidget()
		widget.setLayout(layout)
		self.setCentralWidget(widget)

		self.show()


if __name__ == "__main__":
        ---------  SOME CODE HERE ---------

The graphing code (the code that generates my graph) is shown from HERE 2. HERE 1 marks the setting of values that are only used to generate the graphs.

Should I move all of this into MPLCanvas and, if so, how?

Or is there someone here that is willing to give me a little time to help coach me through this system?

SGaist

Hi,

Shouldn't you create a new MplCanvas object for each file ? Here you are overwriting the content of the object on each iteration.

Also, since you want to make it cleaner, do not call ˋself.show`. It's not the role of the widget to show itself. It's the role of the controlling code to know when to show it.

GaryN

@SGaist
I want the results of each file to be plotted on a single plot; the result I have does this - though, I am not sure this is the most efficient. As I say, the QT information is... unclear.

I followed an example code here for the .show. So, I moved the self.show() to the __main__ section and made it w.show(); sure enough, this worked fine - thank you. That makes sense. Each of the classes defines the object; it is up to the object to declare when and where it appears - right?

SGaist

I am not sure I am following you correctly.

The core idea is that self.show() is a no go especially in constructors (or in the case of Python the __init__ function).