从 PdfFileWriter 创建 blobstore 文件

Question

我正在尝试使用 python 和谷歌应用程序引擎将两个 pdf 与 pyPdf 库合并。 我从 blobstore 读取文件，并使用我需要的信息创建 PdfFileWriter 对象，但随后我无法将这个 PdfFileWriter 转换为 blobstore 文件。 有什么想法可以解决吗？ 谢谢 ：）

这是我的代码：

blob_reader1 = blobstore.BlobReader(blob_key1)
blob_reader2 = blobstore.BlobReader(blob_key2)

writer = PdfFileWriter()

input1 = PdfFileReader(blob_reader1)
input2 = PdfFileReader(blob_reader2)

writer.addPage(input1.getPage(0))
writer.addPage(input1.getPage(1))
writer.addPage(input2.getPage(0))


# finally, write "output" to document-output.pdf
# This lines are comment because it is the way to do it without google app engine---
# outputStream = file("document-output.pdf", "wb")
# output.write(outputStream)
# outputStream.close()
#        
# Open the file and write to it
#I do not how write the information are inside writer in blobstore file
file_name = files.blobstore.create(mime_type='application/pdf')    
#with files.open(file_name, 'a') as f:
#    f.write(writer) it does not work

# Finalize the file. Do this before attempting to read it.
files.finalize(file_name)

blob_key = files.blobstore.get_blob_key(file_name)

Answer 1

您可以尝试将数据输出到字符串缓冲区，然后将缓冲区写入 blob 文件：

import StringIO

stream = StringIO.StringIO()
writer.write( stream )    # write PDF content

# Open the file and write to it
with files.open(file_name, 'a') as f:
    f.write( stream.getvalue() )

然后完成并做通常的事情。