romkan2

romkan2 is a modernized, actively maintained fork of python-romkan, designed as a drop-in replacement for the original library.

This is a Romaji/Kana conversion library for Python, which is used to convert a Japanese Romaji (ローマ字) string to a Japanese Kana (仮名) string or vice versa.

Why romkan2?

The original python-romkan by Mort Yao has not been actively maintained in recent years. This fork aims to:

• Support modern Python versions (3.9+)
• Modernize the codebase with type hints and improved code structure
• Use contemporary Python packaging standards (pyproject.toml)
• Maintain full backward compatibility as a drop-in replacement

Heritage

This library is the Pythonic port of Ruby/Romkan, originally authored by Satoru Takabayashi and ported by Masato Hagiwara, then modernized by Mort Yao.

romkan2 handles both Katakana (片仮名) and Hiragana (平仮名) with the Hepburn (ヘボン式) romanization system, as well as the modern Kunrei-shiki (訓令式) romanization system.

Installation

Install via pip:

pip install romkan2

Or install from source:

git clone https://github.com/altescy/romkan2.git
cd romkan2
pip install -e .

Usage

import romkan2

# Convert Kana to Romaji
print(romkan2.to_roma("にんじゃ"))
# => ninja

print(romkan2.to_hepburn("にんじゃ"))
# => ninja

print(romkan2.to_kunrei("にんじゃ"))
# => ninzya

# Convert Romaji to Kana
print(romkan2.to_hiragana("ninja"))
# => にんじゃ

print(romkan2.to_katakana("ninja"))
# => ニンジャ

API Reference

to_katakana(string: str) -> str

Convert a Romaji (ローマ字) to a Katakana (片仮名).

to_hiragana(string: str) -> str

Convert a Romaji (ローマ字) to a Hiragana (平仮名).

to_kana(string: str) -> str

Convert a Romaji (ローマ字) to a Katakana (片仮名). (same as to_katakana)

to_hepburn(string: str) -> str

Convert a Kana (仮名) or a Kunrei-shiki Romaji (訓令式ローマ字) to a Hepburn Romaji (ヘボン式ローマ字).

to_kunrei(string: str) -> str

Convert a Kana (仮名) or a Hepburn Romaji (ヘボン式ローマ字) to a Kunrei-shiki Romaji (訓令式ローマ字).

to_roma(string: str) -> str

Convert a Kana (仮名) to a Hepburn Romaji (ヘボン式ローマ字).

Migration from python-romkan

romkan2 is a drop-in replacement for python-romkan. Simply replace:

# Old
import romkan

# New
import romkan2 as romkan

License

romkan2 is licensed under the BSD license.

Credits

• Original Ruby/Romkan: Satoru Takabayashi
• Python port: Masato Hagiwara
• python-romkan: Mort Yao
• romkan2 (this fork): Yasuhiro Yamaguchi