How to Work with Font Tables in Python

TrueType fonts store all data in binary tables identified by 4-character tags. Aspose.Font FOSS exposes TtfTableSet for named table access and TtfFont.get_table_bytes() / TtfFont.set_table_bytes() for raw binary access.

Step-by-Step Guide

Step 1: Install the Package

pip install "aspose-font>=1.0.0"

Step 2: Import Required Classes

from aspose_font.loader import FontLoader
from aspose_font.ttf.font import TtfFont

Step 3: Access Named Tables

ttf_font: TtfFont = FontLoader.open("Roboto-Regular.ttf")
tables = ttf_font.ttf_tables
print("kern present:", tables.kern is not None)
print("cmap present:", tables.cmap is not None)

Step 4: Read Raw Table Bytes

ttf_font: TtfFont = FontLoader.open("Roboto-Regular.ttf")
raw = ttf_font.get_table_bytes("name")
print(f"name table: {len(raw)} bytes")

Step 5: Write Modified Table Bytes

ttf_font: TtfFont = FontLoader.open("Roboto-Regular.ttf")
modified = b"..."  # your modified binary data
ttf_font.set_table_bytes("GSUB", modified)

Common Issues and Fixes

AttributeError: Font has no attribute ttf_tables — ttf_tables is on TtfFont, not the base Font class. Use ttf_font: TtfFont = FontLoader.open(...) to get a typed reference.

get_table_bytes returns empty bytes — The tag must be exactly 4 characters (pad with spaces if needed, e.g. "kern" not "KRN").

Frequently Asked Questions

Which named tables are exposed on TtfTableSet?

head, hhea, maxp, os2, name, post, cmap, loca, hmtx, and kern.

Can I add a new table to a font?

Yes. Pass any valid 4-byte tag and byte data to TtfFont.set_table_bytes(tag, data).