banglapdf

Correctly shaped Bangla (Bengali) text in ReportLab PDFs.

রিপোর্টল্যাবে বাংলা লিখলে যুক্তাক্ষর ভেঙে যায়, ি-কার ভুল জায়গায় বসে — banglapdf সেই সমস্যার সমাধান।

The problem

Out of the box, ReportLab renders Bangla like this:

বিজ্‌ঞান, স্‌বাস্‌থ্‌য, প্‌রক্‌রিয়া (broken conjuncts, misplaced kars)

Two things are needed to fix it, and both are easy to get wrong:

1. HarfBuzz shaping must be enabled (shaping=1 on the paragraph style, with uharfbuzz installed) — otherwise conjuncts (ক্ষ, স্থ, দ্ধ) and vowel signs never form.
2. No inline font switching inside shaped paragraphs. Mixed Bangla+English text ("Python-এর সাথে বাংলা") crashes or garbles if you switch fonts mid-word, because shaping runs per text fragment. The fix is a single font that covers both scripts — banglapdf builds one at runtime by merging Noto Sans (Latin) with Noto Sans Bengali using fontTools, and caches it in ~/.cache/banglapdf/.

banglapdf packages both fixes behind a two-line API.

Install

pip install banglapdf

You also need the Noto fonts (already present on most desktop Linux systems):

sudo apt install fonts-noto-core        # Debian / Ubuntu

Any other Latin+Bangla font pair also works — pass explicit paths to register_fonts().

Choosing a Bangla font family

Three named families are built in:

register_fonts()                        # Noto Sans Bengali (default)
register_fonts(family="solaimanlipi")   # SolaimanLipi
register_fonts(family="lohit")          # Lohit Bengali

For SolaimanLipi, download the font from OmicronLab and copy the .ttf into ~/.local/share/fonts/ — banglapdf will find it there. If a family has no bold variant on your system, the regular weight is reused for bold text (with a warning). For anything else, pass explicit paths:

register_fonts(bangla_regular="/path/to/MyBangla.ttf",
               bangla_bold="/path/to/MyBangla-Bold.ttf")

Quickstart

from reportlab.platypus import SimpleDocTemplate
from banglapdf import register_fonts, BanglaParagraph, bangla_style

register_fonts()   # merge + cache + register fonts (names: "Bangla", "BanglaB")

story = [
    BanglaParagraph("আমার সোনার বাংলা, আমি তোমায় ভালোবাসি",
                    bangla_style(bold=True, fontSize=16)),
    BanglaParagraph("যুক্তাক্ষর (ক্ষ, স্থ, দ্ধ), ি-কার এবং English শব্দ — "
                    "সব একসাথে নিখুঁতভাবে render হয়।"),
]
SimpleDocTemplate("demo.pdf").build(story)

API

Everything else is plain ReportLab — tables, frames, doc templates and canvas drawing all work unchanged; just use the "Bangla"/"BanglaB" font names and shaping=1 (which bangla_style already sets).

Requirements

• Python ≥ 3.9
• reportlab ≥ 4.1 (HarfBuzz shaping support)
• uharfbuzz, fonttools (installed automatically)
• A Latin and a Bangla TTF on the system (Noto recommended)

License

MIT © MD. MAHBUB ALOM

The Noto fonts used at runtime are licensed under the SIL Open Font License; this package does not redistribute them — it merges the copies already installed on your system.