在使用Python从base64转换时，如何停止创建损坏的PNG

Question

我已经尝试了多种方法，并且已经搜索了高低，但是无论我尝试什么（包括我可以在此处找到的所有帖子），我都无法将我的base64字符串转换为HTML文档 / canvas包含JavaScript。

我没有遇到很常见的错误填充错误（我确保了“数据：text/html; base64”，在base64字符串的开头中不包括。）

我还通过检查和检查base64字符串，运行原始.html文件，该文件在浏览器中毫无问题，并用在线解码器解码字符串。

我知道我一定在这里缺少一些非常简单的东西，但是几个小时后，我准备将头发拉出。

我的编码步骤如下：

htmlSource = bytes(htmlSource,'UTF-8')
fullBase64 = base64.b64encode(htmlSource)

在下面的尝试中包括最终的base64字符串，该字符串应在4K中的肮脏的白色背景上生成带有阴影的绿松石椭圆形。

以下尝试都创建一个png文件，只有1kb的大小，无法打开 - '它可能损坏或使用预览无法识别的文件格式。”：

import base64

img_data = b'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'

with open("turquoise egg.png", "wb") as fh:
    fh.write(base64.decodebytes(img_data))

版本2

from binascii import a2b_base64

data = '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'
binary_data = a2b_base64(data)

fd = open('turquoise egg.png', 'wb')
fd.write(binary_data)
fd.close()

版本3

import base64
  
fileString = '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'
  
decodeit = open('turquoise egg.png', 'wb')
decodeit.write(base64.b64decode((fileString)))
decodeit.close()

fwiw我最初使用以下代码来从HTML创建PNG而不使用base64，但它只会保存在画布上生成的JavaScript的第一个元素（即背景），并且由于我无论如何都需要Base64中的信息，因此以为我会这样处理它以便以此方式来实现。捕获完整的图像

file = open('html.html', 'r')
    
imgkit.from_file(file, 'png.png')
file.close()

Answer 1

HTML2Image提供了我正在寻找的解决方案。

尽管IMGKT并没有保存完全渲染的画布，但使用HTML2Canvas拍摄屏幕截图。文档为在这里，我实现如下：

from html2image import Html2Image

    hti.screenshot(
        html_file = ‘html.html’, 
        size = (imageW, imageH),
        save_as = ‘png.png'
    )