PyPDF2:流意外结束

Question

我有一个Python脚本，它使用PyPDF2来颠倒PDF的页面顺序。

from  PyPDF2 import PdfFileWriter, PdfFileReader

output = PdfFileWriter()
rpage = []
name = input("What's the file called?")

filename = name.split('.', 1)

input1 = PdfFileReader(open(name,'rb'), strict = False)

pages = list(range(1,input1.getNumPages() + 1))

for i in range(0, (input1.getNumPages())):
    rpage.append(pages[input1.getNumPages() - i -1])
for i in rpage:
    output.addPage(input1.getPage(i-1))

outputpath = filename[0] + '-reversed.pdf'

outputStream = open(outputpath, "wb")
output.write(outputStream)

在尝试写入输出流之前，它会按预期运行，并返回以下错误：

PdfReadWarning: Invalid stream (index 59) within object 108 0: Stream has ended unexpectedly [pdf.py:1573]
Traceback (most recent call last):
  File "D:\Documents\Google Drive\Programming\Python\PDF Scripts\reverse pdf.py", line 22, in <module>
output.write(outputStream)
  File "C:\Users\Charles\Anaconda3\lib\site-packages\PyPDF2\pdf.py", line 482, in write
self._sweepIndirectReferences(externalReferenceMap, self._root)
  File "C:\Users\Charles\Anaconda3\lib\site-packages\PyPDF2\pdf.py", line 571, in _sweepIndirectReferences
self._sweepIndirectReferences(externMap, realdata)
  File "C:\Users\Charles\Anaconda3\lib\site-packages\PyPDF2\pdf.py", line 547, in _sweepIndirectReferences
value = self._sweepIndirectReferences(externMap, value)
  File "C:\Users\Charles\Anaconda3\lib\site-packages\PyPDF2\pdf.py", line 571, in _sweepIndirectReferences
self._sweepIndirectReferences(externMap, realdata)
  File "C:\Users\Charles\Anaconda3\lib\site-packages\PyPDF2\pdf.py", line 547, in _sweepIndirectReferences
    value = self._sweepIndirectReferences(externMap, value)
  File "C:\Users\Charles\Anaconda3\lib\site-packages\PyPDF2\pdf.py", line 556, in _sweepIndirectReferences
    value = self._sweepIndirectReferences(externMap, data[i])
  File "C:\Users\Charles\Anaconda3\lib\site-packages\PyPDF2\pdf.py", line 571, in _sweepIndirectReferences
    self._sweepIndirectReferences(externMap, realdata)
  File "C:\Users\Charles\Anaconda3\lib\site-packages\PyPDF2\pdf.py", line 547, in _sweepIndirectReferences
    value = self._sweepIndirectReferences(externMap, value)
  File "C:\Users\Charles\Anaconda3\lib\site-packages\PyPDF2\pdf.py", line 577, in _sweepIndirectReferences
    newobj = data.pdf.getObject(data)
  File "C:\Users\Charles\Anaconda3\lib\site-packages\PyPDF2\pdf.py", line 1611, in getObject
    retval = readObject(self.stream, self)
  File "C:\Users\Charles\Anaconda3\lib\site-packages\PyPDF2\generic.py", line 66, in readObject
    return DictionaryObject.readFromStream(stream, pdf)
  File "C:\Users\Charles\Anaconda3\lib\site-packages\PyPDF2\generic.py", line 611, in readFromStream
    data["__streamdata__"] = stream.read(length)
TypeError: integer argument expected, got 'NullObject'

代码确实创建了一个PDF文件，但它的大小为0KB，因此不可读。我测试了一个示例脚本来合并三个PDF，发现here会生成另一个空文件，并导致以下错误：

PdfReadWarning: Invalid stream (index 59) within object 108 0: Stream has ended unexpectedly [pdf.py:1573]
Traceback (most recent call last):
  File "C:\Users\Charles\Anaconda3\lib\site-packages\PyPDF2\pdf.py", line 1567, in _getObjectFromStream
    obj = readObject(streamData, self)
  File "C:\Users\Charles\Anaconda3\lib\site-packages\PyPDF2\generic.py", line 98, in readObject
    return NumberObject.readFromStream(stream)
  File "C:\Users\Charles\Anaconda3\lib\site-packages\PyPDF2\generic.py", line 269, in readFromStream
    num = utils.readUntilRegex(stream, NumberObject.NumberPattern)
  File "C:\Users\Charles\Anaconda3\lib\site-packages\PyPDF2\utils.py", line 134, in readUntilRegex
    raise PdfStreamError("Stream has ended unexpectedly")
PyPDF2.utils.PdfStreamError: Stream has ended unexpectedly

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "D:\Documents\Google Drive\Programming\Python\PDF Scripts\untitled1.py", line 27, in <module>
    merger.write(output)
  File "C:\Users\Charles\Anaconda3\lib\site-packages\PyPDF2\merger.py", line 230, in write
    self.output.write(fileobj)
  File "C:\Users\Charles\Anaconda3\lib\site-packages\PyPDF2\pdf.py", line 482, in write
    self._sweepIndirectReferences(externalReferenceMap, self._root)
  File "C:\Users\Charles\Anaconda3\lib\site-packages\PyPDF2\pdf.py", line 571, in _sweepIndirectReferences
    self._sweepIndirectReferences(externMap, realdata)
  File "C:\Users\Charles\Anaconda3\lib\site-packages\PyPDF2\pdf.py", line 547, in _sweepIndirectReferences
    value = self._sweepIndirectReferences(externMap, value)
  File "C:\Users\Charles\Anaconda3\lib\site-packages\PyPDF2\pdf.py", line 571, in _sweepIndirectReferences
    self._sweepIndirectReferences(externMap, realdata)
  File "C:\Users\Charles\Anaconda3\lib\site-packages\PyPDF2\pdf.py", line 547, in _sweepIndirectReferences
    value = self._sweepIndirectReferences(externMap, value)
  File "C:\Users\Charles\Anaconda3\lib\site-packages\PyPDF2\pdf.py", line 556, in _sweepIndirectReferences
    value = self._sweepIndirectReferences(externMap, data[i])
  File "C:\Users\Charles\Anaconda3\lib\site-packages\PyPDF2\pdf.py", line 571, in _sweepIndirectReferences
    self._sweepIndirectReferences(externMap, realdata)
  File "C:\Users\Charles\Anaconda3\lib\site-packages\PyPDF2\pdf.py", line 547, in _sweepIndirectReferences
    value = self._sweepIndirectReferences(externMap, value)
  File "C:\Users\Charles\Anaconda3\lib\site-packages\PyPDF2\pdf.py", line 577, in _sweepIndirectReferences
    newobj = data.pdf.getObject(data)
  File "C:\Users\Charles\Anaconda3\lib\site-packages\PyPDF2\pdf.py", line 1611, in getObject
    retval = readObject(self.stream, self)
  File "C:\Users\Charles\Anaconda3\lib\site-packages\PyPDF2\generic.py", line 66, in readObject
    return DictionaryObject.readFromStream(stream, pdf)
  File "C:\Users\Charles\Anaconda3\lib\site-packages\PyPDF2\generic.py", line 609, in readFromStream
    length = pdf.getObject(length)
  File "C:\Users\Charles\Anaconda3\lib\site-packages\PyPDF2\pdf.py", line 1593, in getObject
    retval = self._getObjectFromStream(indirectReference)
  File "C:\Users\Charles\Anaconda3\lib\site-packages\PyPDF2\pdf.py", line 1576, in _getObjectFromStream
    raise utils.PdfReadError("Can't read object stream: %s"%e)
PyPDF2.utils.PdfReadError: Can't read object stream: Stream has ended unexpectedly

当使用此脚本将PDF拆分为其组成页面时，也会输出前面的错误：

from PyPDF2 import PdfFileWriter, PdfFileReader 
infile = PdfFileReader(open('test.pdf', 'rb'))

for i in range(infile.getNumPages()):
    p = infile.getPage(i)
    outfile = PdfFileWriter()
    outfile.addPage(p)
    with open('page-%02d.pdf' % i, 'wb') as f:
        outfile.write(f)

上面的代码产生了(n-1)个可读的PDF，但第n个PDF是一个空文件。你知道我怎么解决这个问题吗？

Answer 1

你的脚本遍历了几个不同地方的页面，我不清楚这些地方的目的。我相信你倒数的方式是你错误的根源。

我将您的脚本改编为2.7版(因为这就是我正在运行的版本)，然后将其简化为向后遍历您的源文件一次，创建您的反向文件。

from  PyPDF2 import PdfFileWriter, PdfFileReader

output = PdfFileWriter()
# rpage = [] removed because it's not needed anymore
name = raw_input("What's the file called? ") #Changed for the 2.7 environment

filename = name[:-4] #Simplified, since we know where the piece we want is.

input1 = PdfFileReader(name,"rb")
#Simplified, because I couldn't figure out why it was complex.

for i in range(input1.getNumPages(),0,-1): 
     #getNumPages counts like a human and gives the total number of pages
     #This counts backwards, so no need to count forward and use that to
     #reverse the numbers.
     output.addPage(input1.getPage(i-1))
     #getPage counts like a computer and needs to finish with page 0.

outputpath = filename + '-reversed.pdf'

outputStream = open(outputpath, "wb")
output.write(outputStream)
outputStream.close() #Closes the file and stream once you're done.

Answer 2

如果您想要的是能够反转页面以进行打印，而您并不关心尝试保留内部链接和注释，那么pdfrw可能比pyPDF2更适合这项任务：

from  pdfrw import PdfWriter, PdfReader

iname = input("What's the file called? ")
oname = iname.rsplit('.', 1)[0] + '-reversed.pdf'

output = PdfWriter()
output.addpages(reversed(PdfReader(iname).pages))
output.write(oname)

免责声明:我是pdfrw的主要作者。

Answer 3

我建议你使用PyPDF2的'merge‘功能，而不是'addPage’。

以下代码片段详细说明了如何附加和合并文件/页面：

from PyPDF2 import PdfFileMerger

merger = PdfFileMerger()

input1 = open("file1.pdf", "rb")
input2 = open("file2.pdf", "rb")


# add the first 3 pages of first file to output
merger.append(fileobj = input1, pages = (0,3))

# insert the first page of second file into the output beginning after the second page
merger.merge(position = 2, fileobj = input2, pages = (0,1))

# Write to an output PDF document
output = open("document-output.pdf", "wb")
merger.write(output)

删除“append”和“merge”函数中的“pages”参数，以合并文件而不是特定页面。