remove matplotlib hard requirement

Author: ahmedfgad

.github/workflows/main.yml

@@ -80,9 +80,13 @@ jobs:
           python3 -m build
 
       # Install the newly built .whl file to verify the package is installable.
+      # Install with the 'visualize' extra so matplotlib is available for the
+      # plotting tests (tests/test_visualize.py). This also validates that the
+      # optional 'visualize' extra resolves correctly.
       - name: Install PyGAD from Wheel
         run: |
-          pip install dist/*.whl
+          WHEEL=$(ls dist/*.whl)
+          pip install "${WHEEL}[visualize]"
 
       - name: Install PyTest
         run: pip install pytest

README.md

@@ -33,6 +33,16 @@ Install PyGAD with the following command:
 pip install pygad
 ```
 
+PyGAD's core install is intentionally lightweight (only `numpy` and `cloudpickle`). Some features need extra libraries, which are available as optional extras:
+
+```
+# Plotting features (e.g. plot_fitness(), plot_genes()) need matplotlib:
+pip install pygad[visualize]
+
+# Training Keras/PyTorch models (pygad.kerasga, pygad.torchga):
+pip install pygad[deep_learning]
+```
+
 To get started with PyGAD, read the documentation at [Read the Docs](https://pygad.readthedocs.io).
 
 # PyGAD Source Code

pyproject.toml

@@ -42,7 +42,6 @@ classifiers = [
 keywords = ["genetic algorithm", "GA", "optimization", "evolutionary algorithm", "natural evolution", "pygad", "machine learning", "deep learning", "neural networks", "tensorflow", "keras", "pytorch"]
 dependencies = [
   "numpy",
-  "matplotlib",
   "cloudpickle",
 ]
 
@@ -58,6 +57,7 @@ dependencies = [
 
 [project.optional-dependencies]
 deep_learning = ["keras", "tensorflow", "torch"]
+visualize = ["matplotlib"]
 
 # PyTest Configuration. Later, PyTest will support the [tool.pytest] table.
 [tool.pytest.ini_options]

requirements.txt

@@ -1,3 +1,2 @@
 numpy
-matplotlib
 cloudpickle

setup.py

@@ -6,9 +6,10 @@
 setuptools.setup(  
     name="pygad",  
     author="Ahmed Fawzy Gad",
-    install_requires=["numpy", "matplotlib", "cloudpickle",],
+    install_requires=["numpy", "cloudpickle",],
     extras_require={
         "deep_learning": ["keras", "tensorflow", "torch"],
+        "visualize": ["matplotlib"],
     },
     author_email="ahmed.f.gad@gmail.com",