PDF 操作工具集

本技能提供 PDF 文档操作的完整指南。

依赖库

pip install reportlab pypdf pdfplumber

1. 创建 PDF (reportlab)

基础文档

from reportlab.lib.pagesizes import A4, letter
from reportlab.lib.styles import getSampleStyleSheet, ParagraphStyle
from reportlab.lib.units import inch, cm
from reportlab.platypus import (
    SimpleDocTemplate, Paragraph, Spacer, Image,
    Table, TableStyle, PageBreak
)
from reportlab.lib import colors

# 创建文档
doc = SimpleDocTemplate(
    "output.pdf",
    pagesize=A4,
    rightMargin=72,
    leftMargin=72,
    topMargin=72,
    bottomMargin=72
)

# 获取样式
styles = getSampleStyleSheet()

# 构建内容
story = []

# 添加标题
story.append(Paragraph("报告标题", styles['Heading1']))
story.append(Spacer(1, 12))

# 添加段落
story.append(Paragraph("这是正文内容。", styles['Normal']))
story.append(Spacer(1, 12))

# 生成 PDF
doc.build(story)

添加图片

from reportlab.platypus import Image

# 添加图片（指定宽度，保持比例）
img = Image("chart.png", width=400)
story.append(img)

添加表格

from reportlab.platypus import Table, TableStyle
from reportlab.lib import colors

data = [
    ['标题1', '标题2', '标题3'],
    ['数据1', '数据2', '数据3'],
    ['数据4', '数据5', '数据6'],
]

table = Table(data)
table.setStyle(TableStyle([
    ('BACKGROUND', (0, 0), (-1, 0), colors.grey),
    ('TEXTCOLOR', (0, 0), (-1, 0), colors.whitesmoke),
    ('ALIGN', (0, 0), (-1, -1), 'CENTER'),
    ('FONTSIZE', (0, 0), (-1, 0), 14),
    ('BOTTOMPADDING', (0, 0), (-1, 0), 12),
    ('BACKGROUND', (0, 1), (-1, -1), colors.beige),
    ('GRID', (0, 0), (-1, -1), 1, colors.black),
]))

story.append(table)

自定义样式

# 自定义段落样式
custom_style = ParagraphStyle(
    'CustomStyle',
    parent=styles['Normal'],
    fontSize=12,
    leading=16,
    spaceAfter=12,
    textColor=colors.darkblue,
)

2. 合并 PDF (pypdf)

from pypdf import PdfMerger

merger = PdfMerger()

# 添加 PDF 文件
merger.append("file1.pdf")
merger.append("file2.pdf")
merger.append("file3.pdf")

# 写入合并后的文件
merger.write("merged.pdf")
merger.close()

3. 拆分 PDF

from pypdf import PdfReader, PdfWriter

reader = PdfReader("input.pdf")

# 提取特定页面
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)

4. 提取文本 (pdfplumber)

import pdfplumber

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

5. 提取表格

import pdfplumber

with pdfplumber.open("input.pdf") as pdf:
    for page in pdf.pages:
        tables = page.extract_tables()
        for table in tables:
            for row in table:
                print(row)

6. 完整报告示例

from reportlab.lib.pagesizes import A4
from reportlab.lib.styles import getSampleStyleSheet
from reportlab.platypus import (
    SimpleDocTemplate, Paragraph, Spacer, Image, Table, TableStyle, PageBreak
)
from reportlab.lib import colors
from reportlab.lib.units import inch
from datetime import datetime

def create_research_report(
    output_path: str,
    title: str,
    summary: str,
    findings: list,
    charts: list,
    data_table: list
):
    """创建研究报告 PDF"""

    doc = SimpleDocTemplate(output_path, pagesize=A4)
    styles = getSampleStyleSheet()
    story = []

    # 封面
    story.append(Spacer(1, 2*inch))
    story.append(Paragraph(title, styles['Title']))
    story.append(Spacer(1, 0.5*inch))
    story.append(Paragraph(
        f"生成日期: {datetime.now().strftime('%Y-%m-%d')}",
        styles['Normal']
    ))
    story.append(PageBreak())

    # 执行摘要
    story.append(Paragraph("执行摘要", styles['Heading1']))
    story.append(Spacer(1, 12))
    story.append(Paragraph(summary, styles['Normal']))
    story.append(Spacer(1, 24))

    # 关键发现
    story.append(Paragraph("关键发现", styles['Heading1']))
    story.append(Spacer(1, 12))
    for i, finding in enumerate(findings, 1):
        story.append(Paragraph(f"{i}. {finding}", styles['Normal']))
        story.append(Spacer(1, 6))
    story.append(Spacer(1, 24))

    # 图表
    if charts:
        story.append(Paragraph("数据可视化", styles['Heading1']))
        story.append(Spacer(1, 12))
        for chart_path in charts:
            try:
                img = Image(chart_path, width=5*inch)
                story.append(img)
                story.append(Spacer(1, 12))
            except Exception as e:
                story.append(Paragraph(f"图表加载失败: {chart_path}", styles['Normal']))

    # 数据表格
    if data_table:
        story.append(Paragraph("详细数据", styles['Heading1']))
        story.append(Spacer(1, 12))
        table = Table(data_table)
        table.setStyle(TableStyle([
            ('BACKGROUND', (0, 0), (-1, 0), colors.HexColor('#4472C4')),
            ('TEXTCOLOR', (0, 0), (-1, 0), colors.whitesmoke),
            ('ALIGN', (0, 0), (-1, -1), 'CENTER'),
            ('FONTSIZE', (0, 0), (-1, -1), 10),
            ('GRID', (0, 0), (-1, -1), 0.5, colors.grey),
            ('ROWBACKGROUNDS', (0, 1), (-1, -1), [colors.white, colors.HexColor('#E7E6E6')]),
        ]))
        story.append(table)

    # 生成 PDF
    doc.build(story)
    return output_path

# 使用示例
create_research_report(
    output_path="files/reports/research_report.pdf",
    title="市场研究报告",
    summary="本报告分析了...",
    findings=["发现1", "发现2", "发现3"],
    charts=["files/charts/chart1.png", "files/charts/chart2.png"],
    data_table=[
        ["指标", "2023", "2024", "增长率"],
        ["市场规模", "100亿", "120亿", "20%"],
        ["用户数", "1000万", "1500万", "50%"],
    ]
)

注意事项

1. 中文支持：reportlab 默认不支持中文，需要注册中文字体：

   from reportlab.pdfbase import pdfmetrics
   from reportlab.pdfbase.ttfonts import TTFont
   pdfmetrics.registerFont(TTFont('SimHei', 'SimHei.ttf'))
   

2. 图片格式：支持 PNG, JPG, GIF 格式

3. 内存优化：处理大文件时使用流式处理