提取PDF表格
摘要：本文介绍一个提取PDF中的表格内容的程序。首先，程序给出使用示例，最后给出代码开发思路及细节。
作者：yooongchun
表格提取软件下载：
PDF表格提取、发票查验
0.需求说明
- PDF中存在大量表格，需要从表格中提取出指定类型的表格，这些表格主要通过表头和表中的关键字来确定。
1.PDF示例
2.提取规则
提取规则通过Excel指定，如下示例：
3.提取结果示例
提取的结果保存在Excel中，结果如下：
4.使用方法
- 首先准备好
Demo.xlsx文件（下载），同时下载PDFparser.exe程序（下载），将二者放在同一个目录下，然后将PDF文件准备好放在任意文件夹xxx中，将xxx文件夹和以上两个文件放在同一目录下，双击运行程序即可。
5.代码说明
- 程序使用
pdfplumber模块进行PDF解析以获取表格和文本 - 程序使用
xlwt模块和xlrd模块进行Excel的读写 - 程序使用
多进程+多线程模式加快速度 - 程序使用
re模块来使用Python正则表达式
6.代码细节
- PDF解析
# 该类用来实现PDF表格和文字内容的提取
class Extractor(object):
def __init__(self, file_path, rules):
'''
:param file_path:PDF file path
:param rules: extract rules
'''
self.file_path = file_path
self.rules = rules
# 加载PDF文件
def parse_pages(self):
try:
pages = []
pdf = pdfplumber.open(self.file_path)
print('parse file:{} page num:{}'.format(os.path.basename(self.file_path), len(pdf.pages)))
for index, page in enumerate(pdf.pages):
tables = page.extract_tables()
if len(tables) < 1:
continue
pages.append({'text': page.extract_text(), 'tables': tables, 'page': index + 1})
return pages
except Exception as e:
print(e)
return None
# 提取特定类型表头的表格，规则有rules参数指定
def extract_table_with_specific_header(self, pages):
if pages is None or len(pages) < 1:
# print('no-page...')
return
target_tables = []
# 遍历所有页面
for index, page in enumerate(pages):
text = page['text']
tables = page['tables']
page_id = page['page'] - 1
lines = re.split(r'\n+', text)
# 遍历当前页面的所有行
for ind, line in enumerate(lines):
# 判定表头符合规则的表格
if sum([1 for rule in self.rules['in-header'] if re.search(rule, line)]) > 0 and \
sum([1 for rule in self.rules['not-in-header'] if re.search(rule, line)]) == 0:
if ind >= len(lines) - 1:
break
cnt = ind + 1
next = lines[ind + 1]
if ind < len(lines) - 2 and re.search(r'单位[：:]', next):
next = lines[ind + 2]
cnt += 1
for ti, table in enumerate(tables):
if not table:
continue
first = ''.join([word for word in table[0] if word is not None])
# 表格是完整的情况
if first == re.sub(r'\s+', '', next):
tables[ti] = False
if index + 1 < len(pages) and len(pages[index + 1]['tables']) > 0:
table_next = pages[index + 1]['tables'][0]
fi = ''.join([item for item in table_next[0] if item is not None])
if re.sub(r'\s+', '', fi) in re.sub(r'\s+', '', pages[index + 1]['text'][1]):
table += table_next
target_tables.append({'page': page_id + 1, 'method': 'exact', 'table': table,
'table-id': str(page_id + 1) + str(ti + 1)})
# 表格可能不完整的情况
elif first in re.sub(r'\s+', '', next):
tables[ti] = False
if index + 1 < len(pages) and len(pages[index + 1]['tables']) > 0:
table_next = pages[index + 1]['tables'][0]
fi = ''.join([item for item in table_next[0] if item is not None])
if re.sub(r'\s+', '', fi) in re.sub(r'\s+', '', pages[index + 1]['text'][1]):
table += table_next
target_tables.append({'page': page_id + 1, 'method': 'guess', 'table': table,
'table-id': str(page_id + 1) + '-' + str(ti + 1)})
return target_tables
# 提取表格中存在指定类型信息的表格，规则由参数rules指定
def extract_table_with_specific_info(self, pages):
if pages is None or len(pages) < 1:
# print('no-page...')
return
target_tables = []
for index, page in enumerate(pages):
tables = page['tables']
page_id = page['page'] - 1
for ti, table in enumerate(tables):
st = str(table)
if len(self.rules['in-table']) == sum([1 for in_tab in self.rules['in-table'] if in_tab in st]):
if len(self.rules['not-in-table']) == sum(
[1 for not_tab in self.rules['not-in-table'] if not not_tab in st]):
target_tables.append({'page': page_id + 1, 'method': 'content-in-table', 'table': table,
'table-id': str(page_id + 1) + str(ti + 1)})
return target_tables
# 提取存在指定关键词的页面，关键词有rules指定
def extract_specific_page(self, pages):
if pages is None or len(pages) < 1:
# print('no-page...')
return
target_pages = []
for index, page in enumerate(pages):
text = page['text']
page_id = page['page']
if len(self.rules['in-page']) == sum([1 for rule in self.rules['in-page'] if re.search(rule, text)]):
target_pages.append({'page': page_id, 'text': text})
return target_pages
# 执行以上所有过程，返回提取结果
def run(self):
pages = self.parse_pages()
if pages is None or len(pages) < 1:
print('parse pdf error:', os.path.basename(self.file_path))
return
try:
target_1 = self.extract_table_with_specific_header(pages)
target_2 = self.extract_table_with_specific_info(pages)
target_3 = self.extract_specific_page(pages)
tables = []
s = []
for table in target_1:
if table['table-id'] not in s:
s.append(table['table-id'])
tables.append(table)
for table in target_2:
if table['table-id'] not in s:
s.append(table['table-id'])
tables.append(table)
return tables, target_3
except Exception as e:
print(e)- 加载Excel和缓存结果
# 该类用来加载Excel，遍历地址获取PDF文件路径及缓存结果
class Util():
def __init__(self, folder, out, demo):
self.folder = folder
self.out = out
self.demo = demo
# 加载Demo文件，获取rules
def load_demo(self):
print('load demo Excel:', os.path.basename(self.demo))
book = xlrd.open_workbook(self.demo)
sheet = book.sheet_by_index(0)
in_header = sheet.col_values(0, 2, sheet.nrows)
not_in_header = sheet.col_values(1, 2, sheet.nrows)
in_table = sheet.col_values(2, 2, sheet.nrows)
not_in_table = sheet.col_values(3, 2, sheet.nrows)
in_page = sheet.col_values(4, 2, sheet.nrows)
rules = {'in-header': in_header, 'not-in-header': not_in_header, 'in-table': in_table,
'not-in-table': not_in_table, 'in-page': in_page}
for k, v in rules.items():
rules[k] = [i for i in v if not re.sub(r'\s+', '', i) == '']
return rules
# 加载PDF文件，采用迭代遍历
def load_folder(self):
print('load folder:', self.folder)
paths = []
for dirpath, dirnames, filenames in os.walk(self.folder):
for file in filenames:
path = os.path.join(dirpath, file)
if os.path.isfile(path) and (
os.path.splitext(path)[1] == '.pdf' or os.path.splitext(path)[1] == '.PDF'):
paths.append(path)
return paths
# 缓存结果
def save_tmp(self, info, name, code, year):
print('save tmp file:', name)
if not os.path.isdir('tmp'):
os.mkdir('tmp')
tables = info[0]
pages = info[1]
# Excel样式
style = xlwt.XFStyle()
# background color
pattern = xlwt.Pattern()
pattern.pattern = xlwt.Pattern.SOLID_PATTERN
pattern.pattern_fore_colour = 5
style.pattern = pattern
# border
borders = xlwt.Borders()
borders.left = xlwt.Borders.THICK
borders.right = xlwt.Borders.THICK
borders.top = xlwt.Borders.THICK
borders.bottom = xlwt.Borders.THICK
style.borders = borders
# font
font = xlwt.Font()
font.name = 'Times New Roman'
font.bold = True
font.underline = False
font.italic = False
style.font = font
# sheet style-2
style2 = xlwt.XFStyle()
# background color
pattern = xlwt.Pattern()
pattern.pattern = xlwt.Pattern.SOLID_PATTERN
pattern.pattern_fore_colour = 22
style2.pattern = pattern
# border
borders = xlwt.Borders()
borders.left = xlwt.Borders.THICK
borders.right = xlwt.Borders.THICK
borders.top = xlwt.Borders.THICK
borders.bottom = xlwt.Borders.THICK
style2.borders = borders
# font
font = xlwt.Font()
font.name = 'Times New Roman'
font.bold = True
font.underline = False
font.italic = False
style2.font = font
# sheet style-3
style3 = xlwt.XFStyle()
# background color
pattern2 = xlwt.Pattern()
pattern2.pattern = xlwt.Pattern.SOLID_PATTERN
pattern2.pattern_fore_colour = 3
style3.pattern = pattern2
# border
borders = xlwt.Borders()
borders.left = xlwt.Borders.THICK
borders.right = xlwt.Borders.THICK
borders.top = xlwt.Borders.THICK
borders.bottom = xlwt.Borders.THICK
style3.borders = borders
# font
font = xlwt.Font()
font.name = 'Times New Roman'
font.bold = True
font.underline = False
font.italic = False
style3.font = font
# 将数据写如Excel
book = xlwt.Workbook()
sheet1 = book.add_sheet('tables')
sheet2 = book.add_sheet('pages')
for ind, page in enumerate(pages):
page_num = page['page']
text = page['text']
sheet2.write(ind, 0, name)
sheet2.write(ind, 1, code)
sheet2.write(ind, 2, year)
sheet2.write(ind, 3, page_num)
sheet2.write(ind, 4, 'search page')
sheet2.write(ind, 5, text, style)
# save table
i = 0
for ti, table in enumerate(tables):
page = table['page']
method = table['method']
table_content = table['table']
if method == 'exact':
sty = style
elif method == 'guess':
sty = style2
else:
sty = style3
for index, row in enumerate(table_content):
sheet1.write(i, 0, name)
sheet1.write(i, 1, code)
sheet1.write(i, 2, year)
sheet1.write(i, 3, page)
sheet1.write(i, 4, method)
for ind, one in enumerate(row):
sheet1.write(i, 5 + ind, one if one is not None else '', sty)
i += 1
i += 1
book.save('tmp\\' + name + '.tmp.xls')- 执行提取的函数
# 单个文件运行的完整流程，从加载文件到缓存结果的全过程，如果只想使用单线程运行程序，则在主函数中调用该函数即可
def run(rules, file, util):
extractor = Extractor(file, rules)
info = extractor.run()
code = re.findall(r'\d{6}', os.path.basename(file))[0]
year = re.findall(r'\d{8}', os.path.basename(file))[0]
if info is None or len(info[0]) < 1:
with open('noResult.txt', 'a', encoding='utf-8') as fp:
fp.write(file + '\n')
else:
util.save_tmp(info, os.path.basename(file), code, year)- 多进程+多线程
# -------------------
# 以下两个函数是为了加快执行速度而启用的多线程+多进程模式，计算密集型任务状态下进程越多越好（不多于机器CPU核心数）
# -----------------
# 多线程：每次会启动跟files数量相对应的线程来执行，但只能执行在一个CPU核心中
# multiple threads
def batch_processor(func, rules, files, util):
thread_pool = []
for index, file in enumerate(files):
th = threading.Thread(target=func, args=(rules, file, util))
# print('running thread:', th.name)
th.start()
thread_pool.append(th)
for th in thread_pool:
# print('waiting for thread:', th.name)
th.join()
# 多进程：启动4个进程执行，每个进程中运行多线程，CPU有几个核心就使用几个进程，一般机器多为双核心四进程，此时4进程可占满CPU运行，效能最大
# multiple processors
def multi_processor_run(func, sub_func, files, rules, util):
pool = multiprocessing.Pool(processes=4)
cnt = 0
batch_size = 5
while cnt < len(files):
rear = cnt + batch_size
if rear > len(files):
rear = len(files)
batch = files[cnt + 0:rear]
pool.apply_async(func, (sub_func, rules, batch, util))
cnt += batch_size
pool.close()
pool.join()- 整理结果并保存
# 该函数将缓存在本地目录tmp文件夹下的所有临时Excel文件结果整合到一个Excel中
# re-format result
def re_format(sheet_size):
print('re-format file...')
files = os.listdir('tmp')
paths = []
new_book = xlwt.Workbook()
for file in files:
if os.path.isfile(os.path.join('tmp', file)) and '.tmp.xls' in file:
paths.append(os.path.join('tmp', file))
style = xlwt.XFStyle()
# background color
pattern = xlwt.Pattern()
pattern.pattern = xlwt.Pattern.SOLID_PATTERN
pattern.pattern_fore_colour = 5
style.pattern = pattern
# border
borders = xlwt.Borders()
borders.left = xlwt.Borders.THICK
borders.right = xlwt.Borders.THICK
borders.top = xlwt.Borders.THICK
borders.bottom = xlwt.Borders.THICK
style.borders = borders
# font
font = xlwt.Font()
font.name = 'Times New Roman'
font.bold = True
font.underline = False
font.italic = False
style.font = font
# sheet style-2
style2 = xlwt.XFStyle()
# background color
pattern = xlwt.Pattern()
pattern.pattern = xlwt.Pattern.SOLID_PATTERN
pattern.pattern_fore_colour = 22
style2.pattern = pattern
# border
borders = xlwt.Borders()
borders.left = xlwt.Borders.THICK
borders.right = xlwt.Borders.THICK
borders.top = xlwt.Borders.THICK
borders.bottom = xlwt.Borders.THICK
style2.borders = borders
# font
font = xlwt.Font()
font.name = 'Times New Roman'
font.bold = True
font.underline = False
font.italic = False
style2.font = font
# sheet style-3
style3 = xlwt.XFStyle()
# background color
pattern2 = xlwt.Pattern()
pattern2.pattern = xlwt.Pattern.SOLID_PATTERN
pattern2.pattern_fore_colour = 3
style3.pattern = pattern2
# border
borders = xlwt.Borders()
borders.left = xlwt.Borders.THICK
borders.right = xlwt.Borders.THICK
borders.top = xlwt.Borders.THICK
borders.bottom = xlwt.Borders.THICK
style3.borders = borders
# font
font = xlwt.Font()
font.name = 'Times New Roman'
font.bold = True
font.underline = False
font.italic = False
style3.font = font
tab_cnt = 1
page_cnt = 1
tab_rows = 0
page_rows = 0
sheet2 = new_book.add_sheet('pages-' + str(0))
sheet1 = new_book.add_sheet('tables-' + str(0))
sheet1.write(0, 0, 'File')
sheet1.write(0, 1, 'Code')
sheet1.write(0, 2, 'Date')
sheet1.write(0, 3, 'Page')
sheet1.write(0, 4, 'Method')
sheet2.write(0, 0, 'File')
sheet2.write(0, 1, 'Code')
sheet2.write(0, 2, 'Date')
sheet2.write(0, 3, 'Page')
sheet2.write(0, 4, 'Method')
for index, file in enumerate(paths):
book = xlrd.open_workbook(file)
sheet = book.sheet_by_name('tables')
sheet_pages = book.sheet_by_name('pages')
tab_rows += sheet.nrows
page_rows += sheet_pages.nrows
for row in range(sheet.nrows):
if len(sheet.row_values(row)) < 5:
sty1 = None
elif sheet.row_values(row)[4] == 'exact':
sty1 = style
elif sheet.row_values(row)[4] == 'guess':
sty1 = style2
elif sheet.row_values(row)[4] == 'content-in-table':
sty1 = style3
else:
sty1 = None
for col, val in enumerate(sheet.row_values(row)):
if col > 4:
if sty1 is not None:
sheet1.write(tab_cnt, col, val, sty1)
else:
sheet1.write(tab_cnt, col, val)
else:
sheet1.write(tab_cnt, col, val)
tab_cnt += 1
tab_cnt += 1
for row in range(sheet_pages.nrows):
if len(sheet_pages.row_values(row)) < 5:
sty2 = None
elif sheet_pages.row_values(row)[4] == 'exact':
sty2 = style
elif sheet_pages.row_values(row)[4] == 'guess':
sty2 = style2
elif sheet_pages.row_values(row)[4] == 'content-in-table':
sty2 = style3
else:
sty2 = None
for col, val in enumerate(sheet_pages.row_values(row)):
if col > 4:
if sty2 is not None:
sheet2.write(page_cnt, col, val, sty2)
else:
sheet2.write(page_cnt, col, val)
else:
sheet2.write(page_cnt, col, val)
page_cnt += 1
page_cnt += 1
if tab_rows >= sheet_size:
tab_rows = 0
tab_cnt = 1
sheet1 = new_book.add_sheet('tables-' + str(index))
sheet1.write(0, 0, 'File')
sheet1.write(0, 1, 'Code')
sheet1.write(0, 2, 'Date')
sheet1.write(0, 3, 'Page')
sheet1.write(0, 4, 'Method')
if page_rows >= sheet_size:
page_rows = 0
page_cnt = 1
sheet2 = new_book.add_sheet('pages-' + str(index))
sheet2.write(0, 0, 'File')
sheet2.write(0, 1, 'Code')
sheet2.write(0, 2, 'Date')
sheet2.write(0, 3, 'Page')
sheet2.write(0, 4, 'Method')
new_book.save('tables.xls')- 函数入口
# 程序执行入口：主函数
if __name__ == '__main__':
# 此命令是为在Windows环境下打包exe时正确引入多进程模块而添加的，在Python解释器中运行代码这一行是不必要的，当然添加之后也无妨
multiprocessing.freeze_support()
# 程序运行需要的参数
# paras
base_dir = r'./' # 程序工作目录设定为本程序所在的目录
out_path = base_dir + r'\result.xls' # 输出结果文件名称
demo = base_dir + r'\Demo.xlsx' # Demo文件名称
# 新建noResult.txt文件，用来保存没有结果的PDF文件名称
with open('noResult.txt', 'w', encoding='utf-8')as fp:
fp.write(str(datetime.now()) + '\n')
# 初始化Util类
util = Util(base_dir + '\\test', out_path, demo)
rules = util.load_demo()
folder = util.load_folder()
# 执行多进程，，但仅执行单线程模式时这里可替换为run函数
multi_processor_run(batch_processor, run, folder, rules, util)
# 保存结果：5000代表每个Excel的单个sheet最多5000行，超过则会新建sheet
# save...
re_format(5000)
# 移除临时文件，这些临时文件在程序运行过程中会保存在当前目录的tmp文件夹内，其中每个Excel文件保存的是单个PDF文件的结果，最终这些结果将会通过re_format函数整合到一个Excel中，当想要保留这些结果时，可将下面一行代码注释掉
shutil.rmtree('tmp')7.完整项目代码下载地址
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