生成图像的缩略图

pip install pillow

from os.path import expanduser
import const
from core.file_blob_writer import FileBlobWriter
from core.image_thumbnail_generator import ImageThumbnailGenerator
from util.urls import URLUtility

# download the image and get the bytes
img_data = URLUtility(const.ApodEclipseImage()).data

# we will store this in our home folder
fw = FileBlobWriter(expanduser("~"))

# Create a thumbnail generator and scale the image
tg = ImageThumbnailGenerator(img_data).scale(200, 200)

# write the image to a file
fw.write("eclipse_thumbnail.png", tg.bytes)

import io
from PIL import Image

class ImageThumbnailGenerator():
    def __init__(self, bytes):
        # Create a pillow image with the data provided
        self._image = Image.open(io.BytesIO(bytes))

    def scale(self, width, height):
        # call the thumbnail method to create the thumbnail
        self._image.thumbnail((width, height))
        return self

    @property
    def bytes(self):
        # returns the bytes of the pillow image

        # save the image to an in memory objects
        bytesio = io.BytesIO()
        self._image.save(bytesio, format="png")
        # set the position on the stream to 0 and return the underlying data
        bytesio.seek(0)
        return bytesio.getvalue()