利用Python提取PDF文本的简单方法实例

来源：jb51　　时间：2022/7/25 15:26:38　　对本文有异议

第一步，安装工具库

1、tika — 用于从各种文件格式中进行文档类型检测和内容提取

2、wand — 基于 ctypes 的简单 ImageMagick 绑定

3、pytesseract — OCR 识别工具

创建一个虚拟环境，安装这些工具

python -m venv venv
source venv/bin/activate
pip install tika wand pytesseract

第二步，编写代码

假如 pdf 文件里面既有文字，又有图片，以下代码可以直接识别文字：

import io
import pytesseract
import sys
 
from PIL import Image
from tika import parser
from wand.image import Image as wi
 
text_raw = parser.from_file("example.pdf")
print(text_raw['content'].strip())

这还不够，我们还需要能失败图片的部分：

def extract_text_image(from_file, lang='deu', image_type='jpeg', resolution=300):
    print("-- Parsing image", from_file, "--")
    print("---------------------------------")
    pdf_file = wi(filename=from_file, resolution=resolution)
    image = pdf_file.convert(image_type)
    image_blobs = []
    for img in image.sequence:
        img_page = wi(image=img)
        image_blobs.append(img_page.make_blob(image_type))
    extract = []
    for img_blob in image_blobs:
        image = Image.open(io.BytesIO(img_blob))
        text = pytesseract.image_to_string(image, lang=lang)
        extract.append(text)
    for item in extract:
        for line in item.split("\n"):
            print(line)

合并一下，完整代码如下：

import io
import sys
 
from PIL import Image
import pytesseract
from wand.image import Image as wi
from tika import parser
 
def extract_text_image(from_file, lang='deu', image_type='jpeg', resolution=300):
    print("-- Parsing image", from_file, "--")
    print("---------------------------------")
    pdf_file = wi(filename=from_file, resolution=resolution)
    image = pdf_file.convert(image_type)
    for img in image.sequence:
        img_page = wi(image=img)
        image = Image.open(io.BytesIO(img_page.make_blob(image_type)))
        text = pytesseract.image_to_string(image, lang=lang)
        for part in text.split("\n"):
            print("{}".format(part))
 
def parse_text(from_file):
    print("-- Parsing text", from_file, "--")
    text_raw = parser.from_file(from_file)
    print("---------------------------------")
    print(text_raw['content'].strip())
    print("---------------------------------")
 
if __name__ == '__main__':
    parse_text(sys.argv[1])
    extract_text_image(sys.argv[1], sys.argv[2])

第三步，执行

假如 example.pdf 是这样的：

在命令行这样执行：

python run.py example.pdf deu | xargs -0 echo > extract.txt

最终 extract.txt 的结果如下：

-- Parsing text example.pdf --
---------------------------------
Title pure text

Content pure text

Slide 1
Slide 2
---------------------------------
-- Parsing image example.pdf --
---------------------------------
Title pure text

Content pure text

Title in image

Text in image