python - 如何使用图像哈希作为下载图像的文件名？

Question

在 Python 中，我想将图像保存到文件中。文件名应该是哈希值，由 imagehash.average_hash() 生成。使用 ls -l 我看到了文件，但它们是空的:

-rw-r--r--  1 lorem  lorem     0  8 Sep 16:20 c4c0bcb49890bcfc.jpg
-rwxr-xr-x  1 lorem  lorem   837  8 Sep 16:19 minimal.py

代码:

import requests
from PIL import Image
import imagehash
import shutil

def safe_to_file(url):
    headers = {
        'user-agent': 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_11_6) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/53.0.2785.143 Safari/537.36'}
    image_hash = ''
    r = requests.get(url, headers=headers, timeout=10, stream=True)
    try:
        if r.status_code == 200:
            image_hash = str(imagehash.average_hash(Image.open(r.raw))) + '.jpg'
            print(image_hash)
            with open(image_hash, 'wb') as f:
                r.raw.decode_content = True
                shutil.copyfileobj(r.raw, f)
    except Exception as ex:
        print(str(ex))
    finally:
        return image_hash

# Random jpg picture
url = 'https://cdn.ebaumsworld.com/mediaFiles/picture/1035099/85708057.jpg'
safe_to_file(url)

我希望图像不为空。我做错了什么？

Answer 1

正如我所怀疑的那样，PIL.Image 对象的创建会消耗并从 url 下载所有图像数据，因此 shutil.copyfileobj() 无需执行任何操作消费。

下面的代码似乎通过使用所需的基于哈希的文件名显式保存 Image 对象来避免该问题。我添加了注释以指示重大更改。

import imagehash
from PIL import Image
import requests
#import shutil


def safe_to_file(url):
    headers = {'user-agent': 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_11_6) '
                             'AppleWebKit/537.36 (KHTML, like Gecko) '
                             'Chrome/53.0.2785.143 Safari/537.36'}
    image_hash = ''
    r = requests.get(url, headers=headers, timeout=10, stream=True)
    try:
        if r.status_code == 200:
            img = Image.open(r.raw)  # ADDED
            image_hash = str(imagehash.average_hash(img)) + '.jpg'  # CHANGED.
            print('saving image:', image_hash)
            img.save(image_hash)  # ADDED
#            with open(image_hash, 'wb') as f:  # REMOVED
#                r.raw.decode_content = True    # REMOVED
#                shutil.copyfileobj(r.raw, f)   # REMOVED
    except Exception as ex:
        print(str(ex))
    finally:
        return image_hash

# Random jpg picture
url = 'https://cdn.ebaumsworld.com/mediaFiles/picture/1035099/85708057.jpg'
safe_to_file(url)

c4c0bcb49890bcfc.jpg 它创建的文件: