gtfont

Fast string measurement for perfect tables.

gtfont is a Rust-powered Python extension that provides precise text measurement utilities, optimized for building perfectly aligned tables from pandas DataFrames.

This library is designed for use within the greater_tables package, but can also be used standalone.

Features

• Measure the rendered width of a sentence using system fonts
• Compute maximum word width in a line
• Combine both in one efficient call
• Based on native font rendering for accurate results
• Blazing-fast Rust backend exposed as a Python module

Installation

pip install gtfont

Python ≥3.8 is required. Pre-built wheels are available for major platforms via PyPI.

Example

from gtfont import FontMeasurer
from matplotlib import font_manager

font_path = font_manager.findfont("Times New Roman", fallback_to_default=True)
font_bytes = Path(font_path).read_bytes()
fm = FontMeasurer(font_bytes)
sentence = "The quick brown fox jumps over the lazy dog."

# Measure sentence width in points
width = fm.measure(sentence, 11)

# Measure max word width
max_word = fm.max_word_width(sentence, 11)

# Both at once
sentence_width, max_word_width = fm.measure_and_max_word(sentence, 11)

Build

maturin build --release --strip

# or 

maturin develop 

Why Rust?

Font measurement is performance-critical. By leveraging pyo3, we combine the safety and speed of Rust with the usability of Python.

License

MIT © Stephen J. Mildenhall