Registry / data / matplotlib-fontja

matplotlib-fontja

library1.1.0pypypi✓ verified 85d ago

matplotlib-fontja is a Python library designed to easily enable Japanese character display in Matplotlib plots. It automatically detects available Japanese fonts on your system, updates Matplotlib's font cache, and configures `rcParams` to use them. The current version is 1.1.0, with updates typically focusing on compatibility and font detection improvements.

data

pip install matplotlib-fontja

github ↗package ↗changelog ↗

INSTALL

IMPORT

SIG · MATPLOTLIB-FONTJA

matplotlib-fontja

datapythonv1.1.0

Install

7.9s avg

Import

1608ms

Disk

186MB

Pass rate

10/ 10

Env Coverage10 / 10

glibc

3.9–3.13

musl

3.9–3.13

Install & Compatibility

Where this runs

tested against v1.1.0 · pip install

no network on importno background threads

Install × environment matrix

Each cell = how many times install + import succeeded across repeated harness runs. Partial = flaky.
glibc = Debian/Ubuntu slim · musl = Alpine Linux

musl

py 3.10–3.910 runs

installs and imports cleanly · install 0.0s · import 1.636s · 183.4MB

glibc

py 3.10–3.910 runs

installs and imports cleanly · install 7.9s · import 1.579s · 176MB

186MB installed

● package 186MB

Code

Verified usage

Verified import paths — ran on the pinned version, not inferred.

matplotlib_fontja

✓ import matplotlib_fontja

✗ from matplotlib_fontja import set_font

While 'from matplotlib_fontja import set_font' works, the recommended pattern is to import the module and call `matplotlib_fontja.set_font()` for clarity and to indicate it's a module-level configuration.

This quickstart demonstrates how to import `matplotlib-fontja`, apply its font configuration using `set_font()`, and then create a Matplotlib plot that correctly displays Japanese characters.

import matplotlib.pyplot as plt import matplotlib_fontja # Configure Matplotlib to use Japanese fonts matplotlib_fontja.set_font() # Create a simple plot with Japanese text plt.figure(figsize=(8, 6)) plt.plot([1, 2, 3], [1, 4, 9]) plt.title('日本語タイトル (Japanese Title)') plt.xlabel('X軸 (X-axis)') plt.ylabel('Y軸 (Y-axis)') plt.grid(True) plt.show()

Debug

Known issues

gotchaThe library relies on Japanese fonts being installed at the operating system level. If no suitable fonts are found, `set_font()` will warn and Japanese characters may still appear as squares or be missing.

fix

Ensure you have Japanese fonts (e.g., Noto Sans CJK, Yu Gothic, Meiryo) installed on your system. For Linux, refer to your distribution's font installation guides.

affects: All versions

gotchaAlthough `matplotlib-fontja` attempts to rebuild Matplotlib's font cache, sometimes changes aren't immediately reflected, especially in long-running environments like Jupyter notebooks or IDEs.

fix

If Japanese characters still appear as squares, try restarting your Python kernel or development environment. In rare cases, manually clearing the Matplotlib font cache might be necessary: `import matplotlib.font_manager; matplotlib.font_manager._rebuild();`

affects: All versions

gotcha`set_font()` modifies global `matplotlib.rcParams` related to fonts. If you apply other `rcParams` changes after `set_font()`, they might override the Japanese font settings.

fix

Call `matplotlib_fontja.set_font()` early in your script or notebook, ideally before any custom `rcParams` modifications that might conflict with font settings. If you need to override a specific font setting, do so after `set_font()`.

affects: All versions

Errors

Common errors & fixes

UserWarning: No Japanese fonts found on your system. Please install one of the supported fonts for Japanese display.

The `matplotlib-fontja` library could not detect any suitable Japanese fonts installed on your operating system.

fix

Install common Japanese fonts (e.g., Noto Sans CJK JP, Meiryo, Yu Gothic) on your OS. The specific installation method varies by OS (e.g., `apt install fonts-noto-cjk-extra` on Debian/Ubuntu, installing font files on Windows/macOS).

Japanese characters (e.g., こんにちは) appear as empty squares (☐) or generic boxes in Matplotlib plots.

Either no Japanese font is correctly configured for Matplotlib, or Matplotlib's font cache is outdated, or the system lacks Japanese fonts.

fix

First, ensure Japanese fonts are installed on your OS. Then, make sure `matplotlib_fontja.set_font()` is called before `plt.show()`. If the problem persists, restart your Python environment and consider manually rebuilding the font cache: `import matplotlib.font_manager; matplotlib.font_manager._rebuild();`

Upgrade

Version history

1.1.0latest on PyPI · released Apr 24, 2025

Audit

Dependencies

matplotlibrequiredThis library configures Matplotlib's font settings and is a peer dependency.

Agent activity

4 hits · last 30 days

node

Resources

githubhttps://github.com/ciffelia/matplotlib-fontja ↗

packagehttps://pypi.org/project/matplotlib-fontja/ ↗

changeloghttps://github.com/ciffelia/matplotlib-fontja/blob/master/CHANGELOG.md ↗