mojimoji

Common errors

• ModuleNotFoundError: No module named 'mojimoji'

  cause The `mojimoji` Python package is not installed in the current environment or the Python interpreter cannot find it.
  fix Install the library using pip: `pip install mojimoji`.

• Characters (e.g., English letters, numbers) are not converting or are converting unexpectedly alongside Japanese characters.

  cause By default, `mojimoji` converts all supported character categories (kana, digits, ASCII). Users often expect selective conversion without explicitly specifying parameters.
  fix Use the `kana=False`, `digit=False`, or `ascii=False` arguments within `zen_to_han()` or `han_to_zen()` to prevent conversion for specific character types. For example, `mojimoji.zen_to_han('ＡＢＣ１２３', ascii=False)` will keep 'ＡＢＣ' as full-width while converting '１２３'.

• Error during installation: `error: command 'gcc' failed with exit status 1` or similar compilation errors on specific platforms.

  cause As a Cython-based library, `mojimoji` requires a C/C++ compiler toolchain (like `gcc` on Linux/macOS or MSVC on Windows) to be available during installation if a pre-compiled wheel is not available for your specific Python version and architecture.
  fix Ensure you have the necessary build tools installed. For Windows, install 'Build Tools for Visual Studio'. For Linux, install `build-essential` (e.g., `sudo apt-get install build-essential`). For macOS, install Xcode Command Line Tools (`xcode-select --install`).

Warnings

• gotcha By default, `zen_to_han` and `han_to_zen` convert all supported character types (kana, digits, ASCII letters). If you need to convert only specific types (e.g., only kana but not digits), you must explicitly set `kana=False`, `digit=False`, or `ascii=False` for the types you want to exclude from conversion.
  Fix: Use the `kana`, `digit`, and `ascii` keyword arguments to control the conversion scope: `mojimoji.zen_to_han(' text ', kana=False, digit=True)`.
• gotcha This Python `mojimoji` library is specifically for Japanese half-width and full-width character conversion. Be aware that other projects, concepts, or applications (e.g., a Ruby gem, a Discord bot, a social app, or the general Japanese word 'moji moji' meaning fidgeting) share a similar name but are entirely unrelated.
  Fix: Ensure you are using the `studio-ousia/mojimoji` Python package for character conversion and not confusing it with other similarly named projects or concepts.
• bug Backslash characters ('\' and '＼') were not handled properly during conversion in versions prior to 0.0.13, leading to incorrect output for strings containing them.
  Fix: Upgrade to `mojimoji` version 0.0.13 or newer: `pip install --upgrade mojimoji`.

Install

• pip install mojimoji Install latest version

Imports

• mojimoji
  wrong:

  from mojimoji import zen_to_han

  correct:

  import mojimoji

  Functions `zen_to_han` and `han_to_zen` are directly accessible as attributes of the imported `mojimoji` module.

Quickstart

This quickstart demonstrates how to import the `mojimoji` library and use its primary conversion functions, `zen_to_han` and `han_to_zen`, including an example of selective conversion using keyword arguments.

import mojimoji

# Convert full-width to half-width characters
zenkaku_text = 'アイウａｂｃ０１２'
hankaku_text = mojimoji.zen_to_han(zenkaku_text)
print(f"'{zenkaku_text}' (full-width) -> '{hankaku_text}' (half-width)")

# Convert half-width to full-width characters
hankaku_text_2 = 'ｱｲｳabc012'
zenkaku_text_2 = mojimoji.han_to_zen(hankaku_text_2)
print(f"'{hankaku_text_2}' (half-width) -> '{zenkaku_text_2}' (full-width)")

# Selective conversion: convert only digits to half-width
selective_zenkaku = '漢字１２３ひらがなＡＢＣ'
selective_hankaku = mojimoji.zen_to_han(selective_zenkaku, kana=False, ascii=False)
print(f"'{selective_zenkaku}' (selective zen->han) -> '{selective_hankaku}'")