使用for循环在PIL上打开多个图像

Question

I have to open a couple of images with PIL. Right now, i only have 3 images, so I've been doing opening them like so, not within a for-loop:

self.redpic = Image.open("red.png")
self.redpic = self.redpic.resize((100,100), Image.ANTIALIAS)
self.img1 = ImageTk.PhotoImage(self.redpic)

But in the future, I will be opening at least 20 images, so I tried a for-loop implementation:

def process_image(self):
    for valx in range(5):
        self.numbering = "image" + str(valx);
        self.numbpng = numbering + ".png";
        self.numbering = Image.open(numbpng);
        self.numbering = self.numbering.resize((100,100), Image.ANTIALIAS)
        self.numbering= ImageTk.PhotoImage(self.numbering)

But with this, I do not get access to the images that I just created. I've been reading about dynamically creating variables and how it is not recommended, so I was wondering what would be the best way for me to get access to self.imagex where x is an number to an image. I know the number of images ahead of time.

Answer 1

One common way to avoid dynamically creating variables is to store the items in a some sort of variably-sized container, like a tuple , list , dict , etc.

Below is an example of storing them in an class instance attribute which is a list and is named self.images :

from PIL import Image, ImageTk

class Class:
    def process_images(self, num_images):
        self.images = []
        for i in range(num_images):
            image_filename = "image%s.png" % i
            number_img = Image.open(image_filename).resize((100, 100), Image.ANTIALIAS)
            number_img = ImageTk.PhotoImage(number_img)
            self.images.append(number_img)

c = Class()
c.process_images(5)

After calling the method, you can reference individual images like this:

c.images[2]  # Third image.