如何使用PDFMiner从pdf中提取表格？

Question

我正在尝试从pdf文档中的某些表中提取信息。
考虑输入：

Title 1
some text some text some text some text some text
some text some text some text some text some text

Table Title
| Col1          | Col2    | Col3    |
|---------------|---------|---------|
| val11         | val12   | val13   |
| val21         | val22   | val23   |
| val31         | val32   | val33   |

Title 2
some more text some more text some more text some more text
some more text
some more text some more text some more text some more text

我可以这样获得大纲/标题：

path='myFile.pdf'
# Open a PDF file.
fp = open(path, 'rb')
# Create a PDF parser object associated with the file object.
parser = PDFParser(fp)
# Create a PDF document object that stores the document structure.
# Supply the password for initialization.
document = PDFDocument(parser, '')
outlines = document.get_outlines()
for (level,title,dest,a,se) in outlines:
    print (level, title)

这给了我：

(1, u'Title 1')
(2, u'Table Title')
(1, u'Title 2')

这是完美的，因为级别与文本层次结构一致。现在我可以按如下方式提取文本：

if not document.is_extractable:
    raise PDFTextExtractionNotAllowed
# Create a PDF resource manager object that stores shared resources.
rsrcmgr = PDFResourceManager()
# Create a PDF device object.
laparams = LAParams()
device = PDFPageAggregator(rsrcmgr, laparams=laparams)
# Create a PDF interpreter object.
interpreter = PDFPageInterpreter(rsrcmgr, device)
# Process each page contained in the document.
text_from_pdf = open('textFromPdf.txt','w')
for page in PDFPage.create_pages(document):
    interpreter.process_page(page)
    layout = device.get_result()
    for element in layout:
        if isinstance(element, LTTextBox):
            text_from_pdf.write(''.join([i if ord(i) < 128 else ' '
                                            for i in element.get_text()]))

这给了我：

Title 1
some text some text some text some text some text some text some text
some text some text some text some text some text some text some text
Table Title
Col1
val11
val12
val13
Col2
val21
val22
val23
Col3
val31
val32
val33
Title 2
some more text some more text some more text some more text
some more text
some more text some more text some more text some more text

这是有点奇怪的，因为表是以列方式提取的。我可以一行一行地拿到桌子吗？此外，我如何识别表格的开始和结束位置？

Answer 1

如果您只想从PDF文档中提取表格，请查看以下答案：How to extract table as text from the PDF using Python?

从那个答案开始，我尝试了tabula-py，它为我提供了多页PDF的数据表。 tabula-py正确地跳过所有页眉和页脚。以前我曾在同一类型的文档中尝试使用PDFMiner，我提到了同样的问题，有时甚至更糟。

Answer 2

使用camelot从pdf中提取表格