如何从Python中填写的表单中提取PDF字段?

时间:2010-10-21 03:08:58

标签: python forms pdf

我正在尝试使用Python处理一些使用Adobe Acrobat Reader填写和签名的PDF表单。

我试过了:

  • pdfminer演示:它没有转储任何已填写的数据。
  • pyPdf:当我尝试使用PdfFileReader(f)加载文件时,它最多占用一个核心2分钟,我就放弃并杀死了它。
  • Jython和PDFBox:工作得很好但是启动时间太长了,如果这是我唯一的选择,我只需要用直接的Java编写一个外部工具。

我可以继续寻找图书馆并尝试它们,但我希望有人已经为此提供了有效的解决方案。


更新:根据史蒂文的回答,我查看了pdfminer,它很好地完成了这个工作。

from argparse import ArgumentParser
import pickle
import pprint
from pdfminer.pdfparser import PDFParser, PDFDocument
from pdfminer.pdftypes import resolve1, PDFObjRef

def load_form(filename):
    """Load pdf form contents into a nested list of name/value tuples"""
    with open(filename, 'rb') as file:
        parser = PDFParser(file)
        doc = PDFDocument()
        parser.set_document(doc)
        doc.set_parser(parser)
        doc.initialize()
        return [load_fields(resolve1(f)) for f in
                   resolve1(doc.catalog['AcroForm'])['Fields']]

def load_fields(field):
    """Recursively load form fields"""
    form = field.get('Kids', None)
    if form:
        return [load_fields(resolve1(f)) for f in form]
    else:
        # Some field types, like signatures, need extra resolving
        return (field.get('T').decode('utf-16'), resolve1(field.get('V')))

def parse_cli():
    """Load command line arguments"""
    parser = ArgumentParser(description='Dump the form contents of a PDF.')
    parser.add_argument('file', metavar='pdf_form',
                    help='PDF Form to dump the contents of')
    parser.add_argument('-o', '--out', help='Write output to file',
                      default=None, metavar='FILE')
    parser.add_argument('-p', '--pickle', action='store_true', default=False,
                      help='Format output for python consumption')
    return parser.parse_args()

def main():
    args = parse_cli()
    form = load_form(args.file)
    if args.out:
        with open(args.out, 'w') as outfile:
            if args.pickle:
                pickle.dump(form, outfile)
            else:
                pp = pprint.PrettyPrinter(indent=2)
                file.write(pp.pformat(form))
    else:
        if args.pickle:
            print pickle.dumps(form)
        else:
            pp = pprint.PrettyPrinter(indent=2)
            pp.pprint(form)

if __name__ == '__main__':
    main()

7 个答案:

答案 0 :(得分:34)

你应该可以用pdfminer来做,但是需要深入研究pdfminer的内部和一些关于pdf格式的知识(当然是wrt形式,还有关于pdf的内部结构,比如“词典” “和”间接对象“)。

此示例可能会帮助您(我认为它仅适用于简单的情况,没有嵌套字段等...)

import sys
from pdfminer.pdfparser import PDFParser
from pdfminer.pdfdocument import PDFDocument
from pdfminer.pdftypes import resolve1

filename = sys.argv[1]
fp = open(filename, 'rb')

parser = PDFParser(fp)
doc = PDFDocument(parser)
fields = resolve1(doc.catalog['AcroForm'])['Fields']
for i in fields:
    field = resolve1(i)
    name, value = field.get('T'), field.get('V')
    print '{0}: {1}'.format(name, value)

编辑:忘了提及:如果您需要提供密码,请将其传递给doc.initialize()

答案 1 :(得分:5)

Python 3.6 +:

pip install PyPDF2

# -*- coding: utf-8 -*-

from collections import OrderedDict
from PyPDF2 import PdfFileWriter, PdfFileReader


def _getFields(obj, tree=None, retval=None, fileobj=None):
    """
    Extracts field data if this PDF contains interactive form fields.
    The *tree* and *retval* parameters are for recursive use.

    :param fileobj: A file object (usually a text file) to write
        a report to on all interactive form fields found.
    :return: A dictionary where each key is a field name, and each
        value is a :class:`Field<PyPDF2.generic.Field>` object. By
        default, the mapping name is used for keys.
    :rtype: dict, or ``None`` if form data could not be located.
    """
    fieldAttributes = {'/FT': 'Field Type', '/Parent': 'Parent', '/T': 'Field Name', '/TU': 'Alternate Field Name',
                       '/TM': 'Mapping Name', '/Ff': 'Field Flags', '/V': 'Value', '/DV': 'Default Value'}
    if retval is None:
        retval = OrderedDict()
        catalog = obj.trailer["/Root"]
        # get the AcroForm tree
        if "/AcroForm" in catalog:
            tree = catalog["/AcroForm"]
        else:
            return None
    if tree is None:
        return retval

    obj._checkKids(tree, retval, fileobj)
    for attr in fieldAttributes:
        if attr in tree:
            # Tree is a field
            obj._buildField(tree, retval, fileobj, fieldAttributes)
            break

    if "/Fields" in tree:
        fields = tree["/Fields"]
        for f in fields:
            field = f.getObject()
            obj._buildField(field, retval, fileobj, fieldAttributes)

    return retval


def get_form_fields(infile):
    infile = PdfFileReader(open(infile, 'rb'))
    fields = _getFields(infile)
    return OrderedDict((k, v.get('/V', '')) for k, v in fields.items())



if __name__ == '__main__':
    from pprint import pprint

    pdf_file_name = 'FormExample.pdf'

    pprint(get_form_fields(pdf_file_name))

答案 2 :(得分:3)

快速而肮脏的2分钟工作;只需使用PDFminer将PDF转换为xml,然后抓取所有字段。

from xml.etree import ElementTree
from pprint import pprint
import os

def main():
    print "Calling PDFDUMP.py"
    os.system("dumppdf.py -a FILE.pdf > out.xml")

    # Preprocess the file to eliminate bad XML.
    print "Screening the file"
    o = open("output.xml","w") #open for append
    for line in open("out.xml"):
       line = line.replace("&#", "Invalid_XML") #some bad data in xml for formatting info.
       o.write(line) 
    o.close()

    print "Opening XML output"
    tree = ElementTree.parse('output.xml')
    lastnode = ""
    lastnode2 = ""
    list = {}
    entry = {}

    for node in tree.iter(): # Run through the tree..        
        # Check if New node
        if node.tag == "key" and node.text == "T":
            lastnode = node.tag + node.text
        elif lastnode == "keyT":
            for child in node.iter():
                entry["ID"] = child.text
            lastnode = ""

        if node.tag == "key" and node.text == "V":
            lastnode2 = node.tag + node.text
        elif lastnode2 == "keyV":
            for child in node.iter():
                if child.tag == "string":
                    if entry.has_key("ID"):
                        entry["Value"] = child.text
                        list[entry["ID"]] = entry["Value"]
                        entry = {}
            lastnode2 = ""

    pprint(list)

if __name__ == '__main__':
  main()

它不漂亮,只是一个简单的概念证明。我需要为我正在处理的系统实现它,所以我会清理它,但我想我会发布它,以防有人发现它有用。

答案 3 :(得分:3)

更新最新版本的pdf miner(在第一个函数中更改导入和解析器/ doc设置)

from argparse import ArgumentParser
import pickle
import pprint
from pdfminer.pdfparser import PDFParser
from pdfminer.pdfdocument import PDFDocument
from pdfminer.pdftypes import resolve1
from pdfminer.pdftypes import PDFObjRef

def load_form(filename):
    """Load pdf form contents into a nested list of name/value tuples"""
    with open(filename, 'rb') as file:
        parser = PDFParser(file)
        doc = PDFDocument(parser)
        parser.set_document(doc)
        #doc.set_parser(parser)
        doc.initialize()
        return [load_fields(resolve1(f)) for f in
            resolve1(doc.catalog['AcroForm'])['Fields']]

def load_fields(field):
    """Recursively load form fields"""
    form = field.get('Kids', None)
    if form:
        return [load_fields(resolve1(f)) for f in form]
    else:
        # Some field types, like signatures, need extra resolving
        return (field.get('T').decode('utf-8'), resolve1(field.get('V')))

def parse_cli():
    """Load command line arguments"""
    parser = ArgumentParser(description='Dump the form contents of a PDF.')
    parser.add_argument('file', metavar='pdf_form',
        help='PDF Form to dump the contents of')
    parser.add_argument('-o', '--out', help='Write output to file',
        default=None, metavar='FILE')
    parser.add_argument('-p', '--pickle', action='store_true', default=False,
        help='Format output for python consumption')
    return parser.parse_args()

def main():
    args = parse_cli()
    form = load_form(args.file)
    if args.out:
        with open(args.out, 'w') as outfile:
            if args.pickle:
                pickle.dump(form, outfile)
            else:
                pp = pprint.PrettyPrinter(indent=2)
                file.write(pp.pformat(form))
    else:
        if args.pickle:
            print pickle.dumps(form)
        else:
            pp = pprint.PrettyPrinter(indent=2)
            pp.pprint(form)

if __name__ == '__main__':
    main()

答案 4 :(得分:1)

Python PyPDF2包(pyPdf的后继)非常方便:

import PyPDF2
f = PyPDF2.PdfFileReader('form.pdf')
ff = f.getFields()

然后ffdict,其中包含所有相关的表单信息。

答案 5 :(得分:0)

这些行有一个错字:

file.write(pp.pformat(form))

应该是:

outfile.write(pp.pformat(form))

答案 6 :(得分:0)

我创建了一个库来执行此操作: pip install fillpdf

from fillpdf import fillpdfs
fillpdfs.get_form_fields("ex.pdf")

感谢 dvska 的回答,作为库代码的基础。