reportlab-styles

name	reportlab-styles
description	Use reportlab's pre-defined styles from getSampleStyleSheet() correctly

ReportLab Pre-Defined Styles Reference

Overview

ReportLab's reportlab.lib.styles.getSampleStyleSheet() provides a collection of pre-defined paragraph styles. Use these existing styles rather than redefining them to avoid KeyError exceptions.

Available Pre-Defined Styles

The standard stylesheet includes these commonly-used styles:

Style Name	Purpose
Normal	Default body text
Title	Document title (large, bold)
Heading1	Level 1 section heading
Heading2	Level 2 section heading
Heading3	Level 3 section heading
Heading4	Level 4 section heading
Heading5	Level 5 section heading
Heading6	Level 6 section heading
Bullet	Bulleted list items
Definition	Definition list terms
Italic	Italicized text
Code	Monospace code text

Correct Usage Pattern

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

# Get the stylesheet
styles = getSampleStyleSheet()

# Use existing styles directly (CORRECT)
title = Paragraph("My Document Title", styles['Title'])
heading = Paragraph("Section Header", styles['Heading1'])
body = Paragraph("Regular text content", styles['Normal'])

Common Mistake to Avoid

# WRONG - Don't redefine existing style names
from reportlab.lib.styles import getSampleStyleSheet, ParagraphStyle

styles = getSampleStyleSheet()

# This will cause KeyError when you try to use 'Title' later
styles.add(ParagraphStyle(
    name='Title',  # Overwrites the pre-defined 'Title' style
    fontSize=24,
    # ... incomplete definition
))

# Later code expecting the full 'Title' style will fail
paragraph = Paragraph("Title Text", styles['Title'])  # KeyError!

Best Practices

1. Use existing styles as-is when they meet your needs
2. Create new style names for custom styles (e.g., MyCustomTitle, CustomHeading)
3. Base custom styles on existing ones when you need modifications:

from reportlab.lib.styles import getSampleStyleSheet, ParagraphStyle

styles = getSampleStyleSheet()

# Create a NEW style with a unique name
custom_title = ParagraphStyle(
    name='CustomTitle',  # Unique name, doesn't conflict
    parent=styles['Title'],  # Base it on existing Title
    fontSize=28,
    spaceAfter=30
)
styles.add(custom_title)

# Now both styles are available
styles['Title']       # Original pre-defined style
styles['CustomTitle'] # Your custom variant

Quick Reference Checklist

• Import getSampleStyleSheet() from reportlab.lib.styles
• Call styles = getSampleStyleSheet() once at the start
• Access styles via styles['StyleName'] (case-sensitive)
• Do NOT add styles with names that already exist in the stylesheet
• Use unique names for any custom styles you create
• Common available styles: Normal, Title, Heading1-6, Bullet, Code, Italic