PDF 处理指南

概述

本指南介绍使用 Python 库与命令行工具进行常见 PDF 操作。高级用法、JavaScript 库与更多示例见上游仓库的 REFERENCE.md。若需填写 PDF 表单，请阅读 FORMS.md 并按其中步骤操作。

快速开始

from pypdf import PdfReader, PdfWriter

# 读取 PDF
reader = PdfReader("document.pdf")
print(f"Pages: {len(reader.pages)}")

# 提取文本
text = ""
for page in reader.pages:
    text += page.extract_text()

Python 库

pypdf — 基础操作

合并 PDF

from pypdf import PdfWriter, PdfReader

writer = PdfWriter()
for pdf_file in ["doc1.pdf", "doc2.pdf", "doc3.pdf"]:
    reader = PdfReader(pdf_file)
    for page in reader.pages:
        writer.add_page(page)

with open("merged.pdf", "wb") as output:
    writer.write(output)

拆分 PDF

reader = PdfReader("input.pdf")
for i, page in enumerate(reader.pages):
    writer = PdfWriter()
    writer.add_page(page)
    with open(f"page_{i+1}.pdf", "wb") as output:
        writer.write(output)

提取元数据

reader = PdfReader("document.pdf")
meta = reader.metadata
print(f"Title: {meta.title}")
print(f"Author: {meta.author}")
print(f"Subject: {meta.subject}")
print(f"Creator: {meta.creator}")

旋转页面

reader = PdfReader("input.pdf")
writer = PdfWriter()

page = reader.pages[0]
page.rotate(90)  # 顺时针旋转 90°
writer.add_page(page)

with open("rotated.pdf", "wb") as output:
    writer.write(output)

pdfplumber — 文本与表格

按版式提取文本

import pdfplumber

with pdfplumber.open("document.pdf") as pdf:
    for page in pdf.pages:
        text = page.extract_text()
        print(text)

提取表格

with pdfplumber.open("document.pdf") as pdf:
    for i, page in enumerate(pdf.pages):
        tables = page.extract_tables()
        for j, table in enumerate(tables):
            print(f"Table {j+1} on page {i+1}:")
            for row in table:
                print(row)

表格进阶（转 DataFrame）

import pandas as pd

with pdfplumber.open("document.pdf") as pdf:
    all_tables = []
    for page in pdf.pages:
        tables = page.extract_tables()
        for table in tables:
            if table:
                df = pd.DataFrame(table[1:], columns=table[0])
                all_tables.append(df)

if all_tables:
    combined_df = pd.concat(all_tables, ignore_index=True)
    combined_df.to_excel("extracted_tables.xlsx", index=False)

reportlab — 生成 PDF

简单 PDF

from reportlab.lib.pagesizes import letter
from reportlab.pdfgen import canvas

c = canvas.Canvas("hello.pdf", pagesize=letter)
width, height = letter

c.drawString(100, height - 100, "Hello World!")
c.drawString(100, height - 120, "This is a PDF created with reportlab")
c.line(100, height - 140, 400, height - 140)

c.save()

多页文档（Platypus）

from reportlab.lib.pagesizes import letter
from reportlab.platypus import SimpleDocTemplate, Paragraph, Spacer, PageBreak
from reportlab.lib.styles import getSampleStyleSheet

doc = SimpleDocTemplate("report.pdf", pagesize=letter)
styles = getSampleStyleSheet()
story = []

title = Paragraph("Report Title", styles['Title'])
story.append(title)
story.append(Spacer(1, 12))

body = Paragraph("This is the body of the report. " * 20, styles['Normal'])
story.append(body)
story.append(PageBreak())

story.append(Paragraph("Page 2", styles['Heading1']))
story.append(Paragraph("Content for page 2", styles['Normal']))

doc.build(story)

下标与上标

重要：不要在 ReportLab 的 PDF 中使用 Unicode 上下标字符（如 ₀₁₂、⁰¹²），内置字体常不含这些字形，会显示为黑块。

应在 Paragraph 中使用 XML 标记：

from reportlab.platypus import Paragraph
from reportlab.lib.styles import getSampleStyleSheet

styles = getSampleStyleSheet()

# 下标
chemical = Paragraph("H<sub>2</sub>O", styles['Normal'])

# 上标
squared = Paragraph("x<super>2</super> + y<super>2</super>", styles['Normal'])

对 canvas 直接绘制的文字，请通过字号与位置模拟上下标，勿用 Unicode 上下标字符。

命令行工具

pdftotext（poppler-utils）

pdftotext input.pdf output.txt
pdftotext -layout input.pdf output.txt
pdftotext -f 1 -l 5 input.pdf output.txt   # 第 1–5 页

qpdf

qpdf --empty --pages file1.pdf file2.pdf -- merged.pdf
qpdf input.pdf --pages . 1-5 -- pages1-5.pdf
qpdf input.pdf --pages . 6-10 -- pages6-10.pdf
qpdf input.pdf output.pdf --rotate=+90:1
qpdf --password=mypassword --decrypt encrypted.pdf decrypted.pdf

pdftk（若已安装）

pdftk file1.pdf file2.pdf cat output merged.pdf
pdftk input.pdf burst
pdftk input.pdf rotate 1east output rotated.pdf

常见任务

扫描版 PDF 做 OCR

# 需要: pip install pytesseract pdf2image
import pytesseract
from pdf2image import convert_from_path

images = convert_from_path('scanned.pdf')

text = ""
for i, image in enumerate(images):
    text += f"Page {i+1}:\n"
    text += pytesseract.image_to_string(image)
    text += "\n\n"

print(text)

水印

from pypdf import PdfReader, PdfWriter

watermark = PdfReader("watermark.pdf").pages[0]
reader = PdfReader("document.pdf")
writer = PdfWriter()

for page in reader.pages:
    page.merge_page(watermark)
    writer.add_page(page)

with open("watermarked.pdf", "wb") as output:
    writer.write(output)

提取图片

pdfimages -j input.pdf output_prefix

加密

from pypdf import PdfReader, PdfWriter

reader = PdfReader("input.pdf")
writer = PdfWriter()

for page in reader.pages:
    writer.add_page(page)

writer.encrypt("userpassword", "ownerpassword")

with open("encrypted.pdf", "wb") as output:
    writer.write(output)

速查表

| 任务 | 推荐工具 | 说明 | |------|----------|------| | 合并 | pypdf | writer.add_page(page) | | 拆分 | pypdf | 每页单独写出 | | 提取文本 | pdfplumber | page.extract_text() | | 提取表格 | pdfplumber | page.extract_tables() | | 新建 PDF | reportlab | Canvas 或 Platypus | | 命令行合并 | qpdf | qpdf --empty --pages ... | | 扫描件 OCR | pytesseract | 先转图片再识别 | | 填表 | 见 FORMS.md | pdf-lib / pypdf 等 |

后续阅读

进阶 pypdfium2：REFERENCE.md
JavaScript（pdf-lib）：REFERENCE.md
表单填写：FORMS.md
排错：REFERENCE.md

许可证以上游仓库 LICENSE.txt 为准。

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