PltEdit

A simple tool to save matplotlib figures as a unique file and edit them afterward while keeping data integrity

Overview

PltEdit is a Python package that lets you save a matplotlib figure (or axes) — including all its underlying data — to a single .plt file, and reload it in another Python session or in a Streamlit-based GUI.

Unlike matplotlib's built-in savefig() (which exports to raster/vector image formats), a .plt file preserves the full figure object so it can be displayed, inspected, and edited programmatically.

File format

A .plt file is a NumPy archive (.npz) with a custom .plt extension. It contains two arrays:

Key	Content
figure	uint8 array — pickle-serialised matplotlib.figure.Figure
metadata	0-D object array — JSON string with creation info

The metadata JSON includes:

{
  "created_at": "2024-01-15T12:00:00+00:00",
  "python_version": "3.12.3 (main, ...)",
  "matplotlib_version": "3.10.1",
  "pltedit_version": "0.1.0"
}

Installation

# Core library only
pip install pltedit

# With the Streamlit GUI
pip install pltedit[app]

Usage

Python API

import matplotlib.pyplot as plt
import pltedit as plte

# Create a figure
fig, ax = plt.subplots()
ax.plot([1, 2, 3], [4, 5, 6], label="my data")
ax.set_title("My plot")

# Save to .plt
plte.save(fig, "my_figure.plt")

# Load in another session
fig2 = plte.load("my_figure.plt")

# Change style
fig2 = plte.set_style(fig2, "seaborn-v0_8")

# Display
fig2.show()

# Inspect metadata
from pltedit._io import get_metadata
meta = get_metadata("my_figure.plt")
print(meta["created_at"])

You can also pass an Axes object directly to save():

plte.save(ax, "from_axes.plt")

Streamlit GUI

pltedit                        # open the GUI (file upload)
pltedit path/to/figure.plt     # open the GUI with a pre-loaded file

The GUI lets you:

• Upload any .plt file
• View the stored figure metadata
• Edit the figure title, axis labels, and axis limits interactively

Development

git clone https://github.com/VForiel/PltEdit.git
cd PltEdit
pip install -e ".[dev]"
pytest