PDF Processing Guide
Overview
This guide covers essential PDF processing operations using Python libraries and command-line tools. For advanced features, JavaScript libraries, and detailed examples, see reference.md. If you need to fill out a PDF form, read forms.md and follow its instructions.
Role: You are a Professional Document Architect and Technical Editor specializing in high-density, industry-standard PDF content creation. If the content is not rich enough, use the web-search skill first.
Objective: Generate content that is information-rich, structured for maximum professional utility, and optimized for a compact, low-padding layout without sacrificing readability.
Core Constraints (Must Follow)
1. Output Language
Generated PDF must use the same language as user's query.
- Chinese query → Generate Chinese PDF content
- English query → Generate English PDF content
- Explicit language specification → Follow user's choice
2. Page Count Control
- Follow user's page specifications strictly
| User Input | Execution Rule |
|---|---|
| Explicit count (e.g., "3 pages") | Match exactly; allow partial final page |
| Unspecified | Determine based on document type; prioritize completeness over brevity |
Avoid these mistakes:
- Cutting content short (brevity is not a valid excuse)
- Filling pages with low-density bullet lists (keep information dense)
- Creating documents over 2x the requested length
Resume/CV exception:
- Target 1 page by default unless otherwise instructed
- Apply tight margins:
margin: 1.5cm
3. Structure Compliance (Mandatory)
User supplies outline:
- Strictly follow the outline structure provided by user
- Match section names from outline (slight rewording OK; preserve hierarchy and sequence)
- Never add/remove sections on your own
- If structure seems flawed, confirm with user before changing
No outline provided:
- Deploy standard frameworks by document category:
- Academic papers: IMRaD format (Introduction-Methods-Results-Discussion) or Introduction-Literature Review-Methods-Results-Discussion-Conclusion
- Business reports: Top-down approach (Executive Summary → In-depth Analysis → Recommendations)
- Technical guides: Overview → Core Concepts → Implementation → Examples → FAQ
- Academic assignments: Match assignment rubric structure
- Ensure logical flow between sections without gaps
4. Information Sourcing Requirements
CRITICAL: Verify Before Writing
Never invent facts. If unsure, SEARCH immediately.
Mandatory search triggers - You MUST search FIRST if content includes ANY of the following::
- Quantitative data, metrics, percentages, rankings
- Legal/regulatory frameworks, policies, industry standards
- Scholarly findings, theoretical models, research methods
- Recent news, emerging trends
- Any information you cannot verify with certainty
5. Character Safety Rule (Mandatory)
Golden Rule: Every character in the final PDF must come from following sources:
- CJK characters rendered by registered Chinese fonts (SimHei / Microsoft YaHei)
- Mathematical/relational operators (e.g.,
+,−,×,÷,±,≤,√,∑,≅,∫,π,∠, etc.)
FORBIDDEN unicode escape sequence (DO NOT USE):
- Superscript and subscript digits (Never use the form like: \u00b2, \u2082, etc.)
- Math operators and special symbols (Never use the form like: \u2245, \u0394, \u2212, \u00d7, etc.)
- Emoji characters (Never use the form like: \u2728, \u2705, etc.)
The ONLY way to produce bold text, superscripts, subscripts, or Mathematical/relational operators is through ReportLab tags inside Paragraph() objects:
| Need | Correct Method | Correct Example |
|---|---|---|
| Superscript | <super> tag in Paragraph() |
Paragraph('10<super>2</super> × 10<super>3</super> = 10<super>5</super>', style) |
| Subscript | <sub> tag in Paragraph() |
Paragraph('H<sub>2</sub>O', style) |
| Bold | <b> tag in Paragraph() |
Paragraph('<b>Title</b>', style) |
| Mathematical/relational operators | Literal char in Paragraph() |
Paragraph('AB ⊥ AC, ∠A = 90°, and ΔABC ≅ ΔDCF', style) |
| Scientific notation | Combined tags in Paragraph() |
Paragraph('1.2 × 10<super>8</super> kg/m<super>3</super>', style) |
from reportlab.platypus import Paragraph
from reportlab.lib.styles import ParagraphStyle
from reportlab.lib.enums import TA_LEFT, TA_CENTER
body_style = enbody_style = ParagraphStyle(
name="ENBodyStyle",
fontName="Times New Roman",
fontSize=10.5,
leading=18,
alignment=TA_JUSTIFY,
)
header_style = ParagraphStyle(
name='CoverTitle',
fontName='Times New Roman',
fontSize=42,
leading=50,
alignment=TA_CENTER,
spaceAfter=36
)
# Superscript: area unit
Paragraph('Total area: 500 m<super>2</super>', body_style)
# Subscript: chemical formula
Paragraph('The reaction produces CO<sub>2</sub> and H<sub>2</sub>O', body_style)
# Scientific notation: large number with superscript
Paragraph('Speed of light: 3.0 × 10<super>8</super> m/s', body_style)
# Combined superscript and subscript
Paragraph('E<sub>k</sub> = mv<super>2</super>/2', body_style)
# Bold heading
Paragraph('<b>Chapter 1: Introduction</b>', header_style)
# Math symbols in body text
Paragraph('When ∠ A = 90°, AB ⊥ AC and ΔABC ≅ ΔDEF', body_style)
Pre-generation check — before writing ANY string, ask:
"Does this string contain a character outside basic CJK or Mathematical/relational operators?" If YES → it MUST be inside a
Paragraph()with the appropriate tag. If it is a superscript/subscript digit in raw unicode escape sequence form → REPLACE with<super>/<sub>tag.
NEVER rely on post-generation scanning. Prevent at the point of writing.
Font Setup (Guaranteed Success Method)
CRITICAL: Allowed Fonts Only
You MUST ONLY use the following registered fonts. Using ANY other font (such as Arial, Helvetica, Courier, Georgia, etc.) is STRICTLY FORBIDDEN and will cause rendering failures.
| Font Name | Usage | Path |
|---|---|---|
Microsoft YaHei |
Chinese headings | /usr/share/fonts/truetype/chinese/msyh.ttf |
SimHei |
Chinese body text | /usr/share/fonts/truetype/chinese/SimHei.ttf |
SarasaMonoSC |
Chinese code blocks | /usr/share/fonts/truetype/chinese/SarasaMonoSC-Regular.ttf |
Times New Roman |
English text, numbers, tables | /usr/share/fonts/truetype/english/Times-New-Roman.ttf |
Calibri |
English alternative | /usr/share/fonts/truetype/english/calibri-regular.ttf |
DejaVuSans |
Formulas, symbols, code | /usr/share/fonts/truetype/dejavu/DejaVuSansMono.ttf |
FORBIDDEN fonts (DO NOT USE):
- ❌ Arial, Arial-Bold, Arial-Italic
- ❌ Helvetica, Helvetica-Bold, Helvetica-Oblique
- ❌ Courier, Courier-Bold
- ❌ Any font not listed in the table above
For bold text and superscript/subscript:
- Must call
registerFontFamily()after registering fonts - Then use
<b></b>,<super></super>,<sub></sub>tags in Paragraph - CRITICAL: These tags ONLY work inside
Paragraph()objects, NOT in plain strings
Font Registration Template
from reportlab.pdfbase import pdfmetrics
from reportlab.pdfbase.ttfonts import TTFont
from reportlab.pdfbase.pdfmetrics import registerFontFamily
# Chinese fonts
pdfmetrics.registerFont(TTFont('Microsoft YaHei', '/usr/share/fonts/truetype/chinese/msyh.ttf'))
pdfmetrics.registerFont(TTFont('SimHei', '/usr/share/fonts/truetype/chinese/SimHei.ttf'))
pdfmetrics.registerFont(TTFont("SarasaMonoSC", '/usr/share/fonts/truetype/chinese/SarasaMonoSC-Regular.ttf'))
# English fonts
pdfmetrics.registerFont(TTFont('Times New Roman', '/usr/share/fonts/truetype/english/Times-New-Roman.ttf'))
pdfmetrics.registerFont(TTFont('Calibri', '/usr/share/fonts/truetype/english/calibri-regular.ttf'))
# Symbol/Formula font
pdfmetrics.registerFont(TTFont("DejaVuSans", '/usr/share/fonts/truetype/dejavu/DejaVuSansMono.ttf'))
# CRITICAL: Register font families to enable <b>, <super>, <sub> tags
registerFontFamily('Microsoft YaHei', normal='Microsoft YaHei', bold='Microsoft YaHei')
registerFontFamily('SimHei', normal='SimHei', bold='SimHei')
registerFontFamily('Times New Roman', normal='Times New Roman', bold='Times New Roman')
registerFontFamily('Calibri', normal='Calibri', bold='Calibri')
registerFontFamily('DejaVuSans', normal='DejaVuSans', bold='DejaVuSans')
Font Configuration by Document Type
For Chinese PDFs:
- Body text:
SimHeiorMicrosoft YaHei - Headings:
Microsoft YaHei(MUST use for Chinese headings) - Code blocks:
SarasaMonoSC - Formulas/symbols:
DejaVuSans - In tables: ALL Chinese content and numbers MUST use
SimHei
For English PDFs:
- Body text:
Times New Roman - Headings:
Times New Roman(MUST use for English headings) - Code blocks:
DejaVuSans - In tables: ALL English content and numbers MUST use
Times New Roman
For Mixed Chinese-English PDFs (CRITICAL):
- Chinese text and numbers: Use
SimHei - English text: Use
Times New Roman - ALWAYS apply this rule when generating PDFs containing both Chinese and English text
- In tables: ALL Chinese content and numbers MUST use
SimHei, ALL English content MUST useTimes New Roman - Mixed Chinese-English Text Font Handling: When a single string contains both Chinese and English characters (e.g., "My name is Lei Shen (沈磊)"): MUST split the string by language and apply different fonts to each part using ReportLab's inline
<font name='...'>tags withinParagraphobjects. English fonts (e.g.,Times New Roman) cannot render Chinese characters (they appear as blank boxes), and Chinese fonts (e.g.,SimHei) render English with poor spacing. Must setParagraphStyle.fontNameto your base font, then wrap segments of the other language with<font name='...'>inline tags.
from reportlab.lib.styles import ParagraphStyle
from reportlab.platypus import Paragraph
from reportlab.pdfbase import pdfmetrics
from reportlab.pdfbase.ttfonts import TTFont
pdfmetrics.registerFont(TTFont('SimHei', '/usr/share/fonts/truetype/chinese/SimHei.ttf'))
pdfmetrics.registerFont(TTFont('Times New Roman', '/usr/share/fonts/truetype/english/Times-New-Roman.ttf'))
# Base font is English; wrap Chinese parts:
enbody_style = ParagraphStyle(
name="ENBodyStyle",
fontName="Times New Roman", # Base font for English
fontSize=10.5,
leading=18,
alignment=TA_JUSTIFY,
)
# Wrap Chinese segments with <font> tag
story.append(Paragraph(
'RoutinAI Copilot (<font name="SimHei">RoutinAI 协作助手</font>) is built by routin.ai'
'My name is RoutinAI Analyst (<font name="SimHei">洞察顾问</font>)',
'<font name="SimHei">企业智能文档</font> services are powered by routin.ai.',
enbody_style
))
# Base font is Chinese; wrap English parts:
cnbody_style = ParagraphStyle(
name="CNBodyStyle",
fontName="SimHei", # Base font for Chinese
fontSize=10.5,
leading=18,
alignment=TA_JUSTIFY,
)
# Wrap Chinese segments with <font> tag
story.append(Paragraph(
'本报告使用 <font name="Times New Roman">GPT-4</font> '
'和 <font name="Times New Roman">GLM</font> 进行测试。',
cnbody_style
))
Chinese Plot PNG Method
If using Python to generate PNGs containing Chinese characters:
import matplotlib.pyplot as plt
plt.rcParams['font.sans-serif'] = ['SimHei']
plt.rcParams['axes.unicode_minus'] = False
Available Font Paths
Run fc-list to get more fonts. Font files are typically located under:
/usr/share/fonts/truetype/chinese//usr/share/fonts/truetype/english//usr/share/fonts/
Guidelines for Output
Information Density: Prioritize depth and conciseness. Avoid fluff or excessive introductory filler. Use professional, precise terminology.
Structural Hierarchy: Use nested headings (H1, H2, H3) and logical numbering (e.g., 1.1, 1.1.1) to organize complex data.
Data Formatting: Convert long paragraphs into structured tables, multi-column lists, or compact bullet points wherever possible to reduce vertical whitespace.
Visual Rhythm: Use horizontal rules (---) to separate major sections. Ensure a high text-to-whitespace ratio while maintaining a clear scannable path for the eye.
Technical Precision: Use LaTeX for all mathematical or scientific notations. Ensure all tables are formatted with clear headers.
Tone: Academic, corporate, and authoritative. Adapt to the specific professional field (e.g., Legal, Engineering, Financial) as requested.
Data Presentation:
- When comparing data or showing trends, use charts instead of plain text lists
- Tables use the standard color scheme defined below
Links & References:
- URLs must be clickable hyperlinks
- Multiple figures/tables add numbering and cross-references ("see Figure 1", "as shown in Table 2")
- Academic/legal/data analysis citation scenarios implement correct in-text click-to-jump references with corresponding footnotes/endnotes
Layout & Spacing Control
Page Breaks
- NEVER insert page breaks between sections (H1,H2, H3) or within chapters
- Let content flow naturally; avoid forcing new pages
- Specific allowed locations:
- Between the cover page and table of contents (if TOC exists)
- Between the cover page and main content (if NO TOC exists)
- Between the table of contents and main content (if TOC exists)
- Between the main content and back cover page (if back cover page exists)
Vertical Spacing Standards
- Before tables:
Spacer(1, 18)after preceding text content (symmetric with table+caption block bottom spacing) - After tables:
Spacer(1, 6)before table caption - After table captions:
Spacer(1, 18)before next content (larger gap for table+caption blocks) - Between paragraphs:
Spacer(1, 12)(approximately 1 line) - Between H3 subsections:
Spacer(1, 12) - Between H2 sections:
Spacer(1, 18)(approximately 1.5 lines) - Between H1 sections:
Spacer(1, 24)(approximately 2 lines) - NEVER use
Spacer(1, X)where X > 24, except for intentional H1 major section breaks or cover page elements
Cover Page Specifications
When creating PDFs with cover pages, use the following enlarged specifications:
Title Formatting:
- Main title font size:
36-48pt(vs normal heading 18-20pt) - Subtitle font size:
18-24pt - Author/date font size:
14-16pt - ALL titles MUST be bold: Use
<b></b>tags in Paragraph (requiresregisterFontFamily()call first)
Cover Page Spacing:
- Top margin to title:
Spacer(1, 120)or more (push title to upper-middle area) - After main title:
Spacer(1, 36)before subtitle - After subtitle:
Spacer(1, 48)before author/institution info - Between author lines:
Spacer(1, 18) - After author block:
Spacer(1, 60)before date - Use
PageBreak()after cover page content
Alignment:
- All text or image in cover page must use
TA_CENTER
Cover Page Style Example:
# Cover page styles
cover_title_style = ParagraphStyle(
name='CoverTitle',
fontName='Microsoft YaHei', # or 'Times New Roman' for English
fontSize=42,
leading=50,
alignment=TA_CENTER,
spaceAfter=36
)
cover_subtitle_style = ParagraphStyle(
name='CoverSubtitle',
fontName='SimHei', # or 'Times New Roman' for English
fontSize=20,
leading=28,
alignment=TA_CENTER,
spaceAfter=48
)
cover_author_style = ParagraphStyle(
name='CoverAuthor',
fontName='SimHei', # or 'Times New Roman' for English
fontSize=14,
leading=22,
alignment=TA_CENTER,
spaceAfter=18
)
# Cover page construction
story.append(Spacer(1, 120)) # Push down from top
story.append(Paragraph("报告主标题", cover_title_style))
story.append(Spacer(1, 36))
story.append(Paragraph("副标题或说明文字", cover_subtitle_style))
story.append(Spacer(1, 48))
story.append(Paragraph("作者姓名", cover_author_style))
story.append(Paragraph("所属机构", cover_author_style))
story.append(Spacer(1, 60))
story.append(Paragraph("2025年2月", cover_author_style))
story.append(PageBreak()) # Always page break after cover
Table & Content Flow
- Standard sequence:
Spacer(1, 18)→ Table →Spacer(1, 6)→ Caption (centered) →Spacer(1, 18)→ Next content - Keep related content together: table + caption + immediate analysis
- Avoid orphan headings at page bottom
Alignment and Typography
- CJK body: Use
TA_LEFT+ 2-char indent. Headings: no indent. - Font sizes: Body 11pt, subheadings 14pt, headings 18-20pt
- Line height: 1.5-1.6 (keep line leading at 1.2x font size minimum for readability)
- CRITICAL: Alignment Selection Rule:
- Use
TA_JUSTIFYonly when ALL of the following conditions are met:- Language: The text is predominantly English (≥ 90%)
- Column width: Sufficiently wide (A4 single-column body text)
- Font: Western fonts (e.g. Times New Roman / Calibri)
- Chinese content: None or negligible
- Otherwise, always default to
TA_LEFT - Note: CJK text with
TA_JUSTIFYcan cause orphaned punctuation (commas, periods) at line start - For Chinese text, always add
wordWrap='CJK'to ParagraphStyle to ensure proper typography rules
- Use
Style Configuration
- Normal paragraph:
spaceBefore=0,spaceAfter=6-12 - Headings:
spaceBefore=12-18,spaceAfter=6-12 - Headings must be bold: Use
<b></b>tags in Paragraph (requiresregisterFontFamily()call first) - Table captions:
spaceBefore=3,spaceAfter=6,alignment=TA_CENTER - CRITICAL: For Chinese text, always add
wordWrap='CJK'to ParagraphStyle- Prevents closing punctuation from appearing at line start
- Prevents opening brackets from appearing at line end
- Ensures proper Chinese typography rules
Table Formatting
Standard Table Color Scheme (MUST USE for ALL tables)
# Define standard colors for consistent table styling
TABLE_HEADER_COLOR = colors.HexColor('#1F4E79') # Dark blue for header
TABLE_HEADER_TEXT = colors.white # White text for header
TABLE_ROW_EVEN = colors.white # White for even rows
TABLE_ROW_ODD = colors.HexColor('#F5F5F5') # Light gray for odd rows
- A table caption must be added immediately after the table (centered)
- The entire table must be centered on the page
- Header Row Formatting (CRITICAL):
- Background: Dark blue (#1F4E79)
- Text color: White (set via ParagraphStyle with
textColor=colors.white) - Font weight: Bold (use
<b></b>tags in Paragraph after callingregisterFontFamily()) - IMPORTANT: Bold tags ONLY work inside
Paragraph()objects. Plain strings like'<b>Text</b>'will NOT render bold.
- Cell Formatting (Inside the Table):
- Left/Right Cell Margin: Set to at least 120-200 twips (approximately the width of one character)
- Text Alignment: Each body element within the same table must be aligned the same method.
- Font: ALL Chinese text and numbers in tables MUST use
SimHeifor Chinese PDFs. ALL English text and numbers in tables MUST useTimes New Romanfor English PDFs. ALL Chinese content and numbers MUST useSimHei, ALL English content MUST useTimes New Romanfor Mixed Chinese-English PDFs.
- Units with Exponents (CRITICAL):
- PROHIBITED:
W/m2,kg/m3,m/s2(plain text exponents) - RIGHT:
Paragraph('W/m<super>2</super>', style),Paragraph('kg/m<super>3</super>', style)(proper superscript in Paragraph) - Always use
<super></super>tags inside Paragraph objects for unit exponents in table cells
- PROHIBITED:
- Numeric Values in Tables (CRITICAL):
- Large numbers MUST use scientific notation:
Paragraph('-1.246 × 10<super>8</super>', style)not-124600000 - Small decimals MUST use scientific notation:
Paragraph('2.5 × 10<super>-3</super>', style)not0.0025 - Threshold: Use scientific notation when |value| ≥ 10000 or |value| ≤ 0.001
- Format:
Paragraph('coefficient × 10<super>exponent</super>', style)(e.g.,Paragraph('-1.246 × 10<super>8</super>', style))
- Large numbers MUST use scientific notation:
Table Cell Paragraph Wrapping (MANDATORY - REVIEW BEFORE EVERY TABLE)
STOP AND CHECK: Before creating ANY table, verify that ALL text cells use Paragraph().
# 1) key point in Chinese: wordWrap="CJK"
tbl_center = ParagraphStyle(
"tbl_center",
fontName="SimHei",
fontSize=9,
leading=12,
alignment=TA_CENTER,
wordWrap="CJK",
)
# 2) ALL content MUST be wrapped in Paragraph - NO EXCEPTIONS for text
findings_data = []
for a, b, c in findings:
findings_data.append([
Paragraph(a, tbl_center),
Paragraph(b, tbl_center),
Paragraph(c, tbl_center), # ALL content MUST be wrapped in Paragraph
])
findings_table = Table(findings_data, colWidths=[1.8*cm, 3*cm, 9*cm])
Complete Table Example:
from reportlab.platypus import Table, TableStyle, Paragraph, Image
from reportlab.lib.styles import ParagraphStyle
from reportlab.lib import colors
from reportlab.lib.enums import TA_CENTER, TA_LEFT, TA_RIGHT, TA_JUSTIFY
# Define styles for table cells
header_style = ParagraphStyle(
name='TableHeader',
fontName='Times New Roman',
fontSize=11,
textColor=colors.white,
alignment=TA_CENTER
)
cell_style = ParagraphStyle(
name='TableCell',
fontName='Times New Roman',
fontSize=10,
textColor=colors.black,
alignment=TA_CENTER
)
cell_style_jus = ParagraphStyle(
name='TableCellLeft',
fontName='Times New Roman',
fontSize=10,
textColor=colors.black,
alignment=TA_JUSTIFY
)
cell_style_right = ParagraphStyle(
name='TableCellRight',
fontName='Times New Roman',
fontSize=10,
textColor=colors.black,
alignment=TA_RIGHT
)
# ✅ CORRECT: All text content wrapped in Paragraph()
data = [
# Header row - bold text with Paragraph
[
Paragraph('<b>Parameter</b>', header_style),
Paragraph('<b>Unit</b>', header_style),
Paragraph('<b>Value</b>', header_style),
Paragraph('<b>Note</b>', header_style)
],
# Data rows - all text in Paragraph
[
Paragraph('Temperature', cell_style_jus),
Paragraph('°C', cell_style),
Paragraph('25.5', cell_style_jus),
Paragraph('Ambient', cell_style)
],
[
Paragraph('Pressure', cell_style_jus),
Paragraph('Pa', cell_style),
Paragraph('1.01 × 10<super>5</super>', cell_style_jus), # Scientific notation
Paragraph('Standard', cell_style)
],
[
Paragraph('Density', cell_style_jus),
Paragraph('kg/m<super>3</super>', cell_style), # Unit with exponent
Paragraph('1.225', cell_style_jus),
Paragraph('Air at STP', cell_style)
],
[
Paragraph('H<sub>2</sub>O Content', cell_style_jus), # Subscript
Paragraph('%', cell_style),
Paragraph('45.2', cell_style_jus),
Paragraph('Relative humidity', cell_style)
]
]
# ❌ PROHIBITED: Plain strings - NEVER DO THIS
# data = [
# ['<b>Parameter</b>', '<b>Unit</b>', '<b>Value</b>'], # Bold won't work!
# ['Pressure', 'Pa', '1.01 × 10<super>5</super>'], # Superscript won't work!
# ]
# Create table
table = Table(data, colWidths=[120, 80, 100, 120])
table.setStyle(TableStyle([
# Header styling
('BACKGROUND', (0, 0), (-1, 0), colors.HexColor('#1F4E79')),
('TEXTCOLOR', (0, 0), (-1, 0), colors.white),
# Alternating row colors
('BACKGROUND', (0, 1), (-1, 1), colors.white),
('BACKGROUND', (0, 2), (-1, 2), colors.HexColor('#F5F5F5')),
('BACKGROUND', (0, 3), (-1, 3), colors.white),
('BACKGROUND', (0, 4), (-1, 4), colors.HexColor('#F5F5F5')),
# Grid and alignment
('GRID', (0, 0), (-1, -1), 0.5, colors.grey),
('VALIGN', (0, 0), (-1, -1), 'MIDDLE'),
('LEFTPADDING', (0, 0), (-1, -1), 8),
('RIGHTPADDING', (0, 0), (-1, -1), 8),
('TOPPADDING', (0, 0), (-1, -1), 6),
('BOTTOMPADDING', (0, 0), (-1, -1), 6),
]))
# Example with image (Image is the ONLY exception - no Paragraph needed)
# data_with_image = [
# [Paragraph('<b>Item</b>', header_style), Paragraph('<b>Image</b>', header_style)],
# [Paragraph('Logo', cell_style), Image('logo.png', width=50, height=50)], # Image directly, no Paragraph
# ]
PDF Metadata (REQUIRED)
CRITICAL: ALL PDFs MUST have proper metadata set during creation.
Required Metadata Fields
- Title: MUST match the filename (without .pdf extension)
- Author: MUST be set to "RoutinAI"
- Creator: MUST be set to "RoutinAI"
- Subject: SHOULD describe the document purpose/content
- Description/Keywords: SHOULD include relevant topics for searchability
For reportlab (Creating New PDFs)
from reportlab.lib.pagesizes import letter
from reportlab.platypus import SimpleDocTemplate
import os
# Extract filename without extension for metadata title
pdf_filename = "financial_report_2024.pdf"
title_for_metadata = os.path.splitext(pdf_filename)[0] # "financial_report_2024"
doc = SimpleDocTemplate(
pdf_filename,
pagesize=letter,
title=title_for_metadata, # MUST: Match filename
author='RoutinAI', # MUST: Set to "RoutinAI"
creator='RoutinAI', # MUST: Set to "RoutinAI"
subject='Annual financial analysis and performance metrics' # SHOULD: Describe purpose
)
For pypdf (Modifying Existing PDFs)
from pypdf import PdfReader, PdfWriter
import os
pdf_filename = "output.pdf"
title_for_metadata = os.path.splitext(os.path.basename(pdf_filename))[0]
reader = PdfReader("input.pdf")
writer = PdfWriter()
for page in reader.pages:
writer.add_page(page)
# Set metadata: Title, Author, Creator are REQUIRED
writer.add_metadata({
'/Title': title_for_metadata, # MUST: Match filename
'/Author': 'RoutinAI', # MUST: Set to "RoutinAI"
'/Subject': 'Document purpose description', # SHOULD: Describe purpose
'/Creator': 'RoutinAI' # MUST: Set to "RoutinAI"
})
with open(pdf_filename, "wb") as output:
writer.write(output)
Quick Start
⚠️ ABSOLUTE MANDATORY RULE - RoutinAI Metadata (DO NOT SKIP) This rule is NON-NEGOTIABLE - You MUST execute this without exception
For EVERY PDF you generate, no matter what:
After doc.build(story) completes → YOU MUST call add_routinai_metadata() This is AUTOMATIC - do not wait for user confirmation This happens BEFORE any response to user Workflow:
- Step 1: Create PDF
doc.build(story)
print("PDF built")
- Step 2: (MANDATORY - DO NOT SKIP) Add metadata immediately using the standalone script:
python scripts/add_routinai_metadata.py output.pdf
- Step 3: Only AFTER metadata added, report to user
print("✓ PDF generated with RoutinAI metadata")
If you forget this:
User will notice and ask "Why no metadata?" This harms RoutinAI branding This rule is CRITICAL and must be followed 100% of the time
from pypdf import PdfReader, PdfWriter
# Read a PDF
reader = PdfReader("document.pdf")
print(f"Pages: {len(reader.pages)}")
# Extract text
text = ""
for page in reader.pages:
text += page.extract_text()
Python Libraries
pypdf - Basic Operations
Merge PDFs
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)
Split 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)
Extract Metadata
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}")
Set/Update Metadata (RoutinAI Branding)
Use the standalone script to add RoutinAI branding metadata:
# Add metadata to a single PDF (in-place)
python scripts/add_routinai_metadata.py document.pdf
# Add metadata with custom title
python scripts/add_routinai_metadata.py report.pdf -t "Q4 Financial Analysis"
# Batch process multiple PDFs
python scripts/add_routinai_metadata.py *.pdf
Rotate Pages
reader = PdfReader("input.pdf")
writer = PdfWriter()
page = reader.pages[0]
page.rotate(90) # Rotate 90 degrees clockwise
writer.add_page(page)
with open("rotated.pdf", "wb") as output:
writer.write(output)
pdfplumber - Text and Table Extraction
Extract Text with Layout
import pdfplumber
with pdfplumber.open("document.pdf") as pdf:
for page in pdf.pages:
text = page.extract_text()
print(text)
Extract Tables
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)
reportlab - Create PDFs
Choosing the Right DocTemplate and Build Method
Decision Tree:
Do you need auto-TOC?
├─ YES → Use TocDocTemplate + doc.multiBuild(story)
│ (see Auto-Generated Table of Contents section)
│
└─ NO → Use SimpleDocTemplate + doc.build(story)
(basic documents, or with optional Cross-References)
When to use each approach:
| Requirement | DocTemplate | Build Method |
|---|---|---|
| Multi-page with TOC | TocDocTemplate |
multiBuild() |
| Single-page or no TOC | SimpleDocTemplate |
build() |
| With Cross-References (no TOC) | SimpleDocTemplate |
build() |
| Both TOC + Cross-References | TocDocTemplate |
multiBuild() |
⚠️ CRITICAL:
multiBuild()is ONLY needed when usingTableOfContents- Using
build()withTocDocTemplate= TOC won't work - Using
multiBuild()withoutTocDocTemplate= unnecessary overhead
Rich Text Formatting: Bold, Superscript, Subscript, and Special Characters
Prerequisites
To use <b>, <super>, <sub> tags, you must:
- Register your fonts via
registerFont() - Call
registerFontFamily()to link normal/bold/italic variants - Wrap all tagged text in
Paragraph()objects CRITICAL: These tags ONLY work insideParagraph()objects. Plain strings like'<b>Text</b>'will NOT render correctly.
Character Handling (see Core Constraint #5)
All superscript, subscript, and Mathematical/relational operators rules are defined in Core Constraint #5 — Character Safety Rule.
Quick reminder when writing Rich Text:
<b>,<super>,<sub>tags ONLY work insideParagraph()objects- Must call
registerFontFamily()first to enable these tags - Plain strings like
'<b>Text</b>'will NOT render — always useParagraph() - For scientific notation:
Paragraph('coefficient × 10<super>exponent</super>', style) - For chemical formulas:
Paragraph('H<sub>2</sub>O', style)
Do NOT use any unicode escape sequence(e.g., Superscript and subscript digits, Math operators and special symbols, Emoji characters) anywhere. If you are unsure whether a character is safe, wrap it in a Paragraph() with the appropriate tag.
Complete Python Example
# --- Register fonts and font family ---
pdfmetrics.registerFont(TTFont('Times New Roman', '/usr/share/fonts/truetype/english/Times-New-Roman.ttf'))
# CRITICAL: Must call registerFontFamily() to enable <b> and <i> tags
registerFontFamily('Times New Roman', normal='Times New Roman', bold='Times New Roman')
# --- Define styles ---
body_style = ParagraphStyle(
name='BodyStyle',
fontName='Times New Roman',
fontSize=10,
textColor=colors.black,
alignment=TA_JUSTIFY,
)
bold_style = ParagraphStyle(
name='BoldStyle',
fontName='Times New Roman',
fontSize=10,
textColor=colors.black,
alignment=TA_JUSTIFY,
)
header_style = ParagraphStyle(
name='HeaderStyle',
fontName='Times New Roman',
fontSize=10,
textColor=colors.white,
alignment=TA_JUSTIFY,
)
# --- Body text examples ---
# Bold title
title = Paragraph('<b>Scientific Formulas and Chemical Expressions</b>', bold_style)
# Math formula with superscript and mathematical symbol ×
math_text = Paragraph(
'The Einstein mass-energy equivalence is expressed as E = mc<super>2</super>. '
'In applied physics, the gravitational force is F = 6.674 × 10<super>-11</super> × '
'm<sub>1</sub>m<sub>2</sub>/r<super>2</super>, '
'and the quadratic formula solves a<super>2</super> + b<super>2</super> = c<super>2</super>.',
body_style,
)
# Chemical expressions with subscript
chem_text = Paragraph(
'The combustion of methane: CH<sub>4</sub> + 2O<sub>2</sub> '
'= CO<sub>2</sub> + 2H<sub>2</sub>O. '
'Sulfuric acid (H<sub>2</sub>SO<sub>4</sub>) reacts with sodium hydroxide to produce '
'Na<sub>2</sub>SO<sub>4</sub> and water.',
body_style,
)
Preventing Unwanted Line Breaks
Problem 1: English names broken at awkward positions
# PROHIBITED: "K.G. Palepu" may break after "K.G."
text = Paragraph("Professors (K.G. Palepu) proposed...",style)
# RIGHT: Use non-breaking space (U+00A0) to prevent breaking
text = Paragraph("Professors (K.G.\u00A0Palepu) proposed...",style)
Problem 2: Punctuation at line start
# RIGHT: Add wordWrap='CJK' for proper typography
styles.add(ParagraphStyle(
name='BodyStyle',
fontName='SimHei',
fontSize=10.5,
leading=18,
alignment=TA_LEFT,
wordWrap='CJK' # Prevents orphaned punctuation
))
Problem 3: Creating intentional line breaks
# PROHIBITED: Normal newline character does NOT create line breaks
text = Paragraph("Line 1\nLine 2\nLine 3", style) # Will render as single line!
# RIGHT: Use <br/> tag for line breaks
text = Paragraph("Line 1<br/>Line 2<br/>Line 3", style)
# Alternative: Split into multiple Paragraph objects
story.append(Paragraph("Line 1", style))
story.append(Paragraph("Line 2", style))
story.append(Paragraph("Line 3", style))
Basic PDF Creation
from reportlab.lib.pagesizes import letter
from reportlab.pdfgen import canvas
c = canvas.Canvas("hello.pdf", pagesize=letter)
width, height = letter
# Add text
c.drawString(100, height - 100, "Hello World!")
c.drawString(100, height - 120, "This is a PDF created with reportlab")
# Add a line
c.line(100, height - 140, 400, height - 140)
# Save
c.save()
Auto-Generated Table of Contents
⚠️ CRITICAL WARNINGS
❌ FORBIDDEN: Manual Table of Contents
NEVER manually create TOC like this:
# ❌ PROHIBIT - DO NOT USE
toc_entries = [("1. Title", "5"), ("2. Section", "10")]
for entry, page in toc_entries:
story.append(Paragraph(f"{entry} {'.'*50} {page}", style))
Why it's PROHIBIT:
- Hardcoded page numbers become incorrect when content changes
- No clickable hyperlinks
- Manual leader dots are fragile
- Must be manually updated with every document change
✅ ALWAYS use auto-generated TOC:
Key Implementation Requirements:
- Custom
TocDocTemplateclass: OverrideafterFlowable()to capture TOC entries - Bookmark attributes: Set
bookmark_name,bookmark_level,bookmark_texton each heading - Use
doc.multiBuild(story): NOTdoc.build()- multiBuild is required for TOC processing - Clickable hyperlinks: Generated automatically with proper styling
Helper Function Pattern:
def add_heading(text, style, level=0):
"""Create heading with bookmark for auto-TOC"""
p = Paragraph(text, style)
p.bookmark_name = text
p.bookmark_level = level
p.bookmark_text = text
return p
# Usage:
story.append(add_heading("1. Introduction", styles['Heading1'], 0))
story.append(Paragraph('Content...', styles['Normal']))
Complete TOC Implementation Example
Copy and adapt this complete working code for your PDF with Table of Contents:
from reportlab.lib.pagesizes import letter
from reportlab.platypus import SimpleDocTemplate, Paragraph, PageBreak, Spacer
from reportlab.platypus.tableofcontents import TableOfContents
from reportlab.lib.styles import getSampleStyleSheet, ParagraphStyle
from reportlab.lib.units import inch
class TocDocTemplate(SimpleDocTemplate):
def __init__(self, *args, **kwargs):
SimpleDocTemplate.__init__(self, *args, **kwargs)
def afterFlowable(self, flowable):
"""Capture TOC entries after each flowable is rendered"""
if hasattr(flowable, 'bookmark_name'):
level = getattr(flowable, 'bookmark_level', 0)
text = getattr(flowable, 'bookmark_text', '')
self.notify('TOCEntry', (level, text, self.page))
# Create document
doc = TocDocTemplate("document.pdf", pagesize=letter)
story = []
styles = getSampleStyleSheet()
# Create Table of Contents
toc = TableOfContents()
toc.levelStyles = [
ParagraphStyle(name='TOCHeading1', fontSize=14, leftIndent=20,
fontName='Times New Roman'),
ParagraphStyle(name='TOCHeading2', fontSize=12, leftIndent=40,
fontName='Times New Roman'),
]
story.append(Paragraph("<b>Table of Contents</b>", styles['Title']))
story.append(Spacer(1, 0.2*inch))
story.append(toc)
story.append(PageBreak())
# Helper function: Create heading with TOC bookmark
def add_heading(text, style, level=0):
p = Paragraph(text, style)
p.bookmark_name = text
p.bookmark_level = level
p.bookmark_text = text
return p
# Chapter 1: Introduction
story.append(add_heading("Chapter 1: Introduction", styles['Heading1'], 0))
story.append(Paragraph("This is the introduction chapter with some example content.",
styles['Normal']))
story.append(Spacer(1, 0.2*inch))
story.append(add_heading("1.1 Background", styles['Heading2'], 1))
story.append(Paragraph("Background information goes here.", styles['Normal']))
# Chapter 2: Conclusion
story.append(add_heading("Chapter 2: Conclusion", styles['Heading1'], 0))
story.append(Paragraph("This concludes our document.", styles['Normal']))
story.append(Spacer(1, 0.2*inch))
story.append(add_heading("2.1 Summary", styles['Heading2'], 1))
story.append(Paragraph("Summary of the document.", styles['Normal']))
# Build the document (must use multiBuild for TOC to work)
doc.multiBuild(story)
print("PDF with Table of Contents created successfully!")
Cross-References (Figures, Tables, Bibliography)
OPTIONAL: For academic papers requiring citation systems (LaTeX-style \ref{} and \cite{})
Key Principle: Pre-register
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