List change after copy Python

I’m coding the final part of a clustering program, I want to parse a file like

--
COLOR
-
POINT COLOR
...

where

COLOR = (R,G,B)
POINT = (X,Y)

Example:

--
(255,0,4)
-
(0,0) (255,0,4)
(0,1) (255,0,4)
(0,2) (255,0,4)
(0,3) (255,0,4)
--
(32,32,12)
-
(1,0) (156,0,42)
(1,1) (156,0,42)
(1,2) (156,0,42)
(1,3) (156,0,42)

I want to save all this information in different classes to process the data easier.

Here is my code in python:

#!/usr/bin/env python3

import sys

class Point:
    def __init__(self, x, y):
        self.x = x
        self.y = y

class Color:
    def __init__(self, r, g, b):
        self.r = r
        self.g = g
        self.b = b

class Pixel:
    def __init__(self, point, color):
        self.point = point
        self.color = color

class Cluster:
    def __init__(self, meanColor, pixels):
        self.meanColor = meanColor
        self.pixels = pixels

def printCluster(cl):
    print("---------------")
    print("(" + str(cl.meanColor.r) + "," + str(cl.meanColor.g) + "," + str(cl.meanColor.b) + ")")
    print("I have " + str(len(pixels)) + " pixels.")
    for px in pixels:
        print("(" + str(px.point.x) + "," + str(px.point.y) + ") (" + str(px.color.r) + "," + str(px.color.g) + "," + str(px.color.b) + ")")

def printClusters(clusters):
    for cl in clusters:
        printCluster(cl)

def getColor(line):
    r = int(line.split(',')[0][1:])
    g = int(line.split(',')[1])
    b = int(line.split(',')[2][:-1])
    color = Color(r,g,b)
    return (color)


file = open(sys.argv[1], 'r')

meanColor = None
clusters = []
cluster = ""
pixels = []

import copy

count = 0
file.readline()
line = file.readline().rstrip('n')
meanColor = getColor(line)
file.readline()
while True:
    count += 1
    line = file.readline().rstrip('n')
    if (line == "--"):
        pixelsCopy = list(pixels)
        cluster = Cluster(meanColor, pixelsCopy)
        printClusters(clusters)
        printCluster(cluster)
        clusters.append(cluster)
        pixels = []
        printCluster(cluster)
        line = file.readline().rstrip('n')
        meanColor = getColor(line)
        file.readline()
    elif (line and line != "--"):
        print("-------------------------------")
        printClusters(clusters)
        print("line: ~" + line + "~")
        x = int(line.split()[0].split(',')[0][1:])
        y = int(line.split()[0].split(',')[1][:-1])
        print("x: " + str(x))
        print("y: " + str(y))
        point = Point(x,y)
        r = int(line.split()[1].split(',')[0][1:])
        g = int(line.split()[1].split(',')[1])
        b = int(line.split()[1].split(',')[2][:-1])
        print("r: " + str(r))
        print("g: " + str(g))
        print("b: " + str(b))
        color = Color(r,g,b)
        pixels.append(Pixel(point, color))
    if not line:
        pixelsCopy = list(pixels)
        cluster = Cluster(meanColor, pixelsCopy)
        clusters.append(cluster)
        #printCluster(cluster)
        break

printClusters(clusters)

For some reason, after the while loop, when I print all clusters objects, I see that all contains the same pixels list, I try to do a copy with deepcopy, with [:] and with list() but makes no sense. I don’t know where my error is, also I print the cluster after reset to [] and I see that is save like a reference list but I don’t know why if I use list() to make a copy.

Thanks!

Answer

You need Cluster instance’s attribute named pixels:

def printCluster(cl):
    print("---------------")
    print("(" + str(cl.meanColor.r) + "," + str(cl.meanColor.g) + "," + str(cl.meanColor.b) + ")")
    print("I have " + str(len(pixels)) + " pixels.")
    for px in cl.pixels:
        print("(" + str(px.point.x) + "," + str(px.point.y) + ") (" + str(px.color.r) + "," + str(px.color.g) + "," + str(px.color.b) + ")")

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Answer