Remove call to deprecated importlib find_loader (#31)

* remove call to deprecated importlib find_loader

* bump version for release

* edit readme for mazelib issue and add small example

Author: smorad

.pre-commit-config.yaml

@@ -13,7 +13,7 @@ repos:
         name: isort (python)
         args: ["--profile", "black"]
   - repo: https://github.com/pycqa/flake8
-    rev: 4.0.1
+    rev: 7.0.0
     hooks:
       - id: flake8
         args: 

README.md

@@ -9,9 +9,24 @@ Please see the [documentation](https://popgym.readthedocs.io/en/latest/) for adv
 ## Quickstart Install
 
 ```python
-pip install popgym # base environments only, only requires numpy and gymnasium
-pip install --use-pep517 "popgym[navigation]" # also include navigation environments, which require mazelib
-pip install "popgym[baselines]" # environments and memory baselines
+# Install base environments, only requires numpy and gymnasium
+pip install popgym 
+# Also include navigation environments, which require mazelib
+# NOTE: navigation envs require python <3.12 due to mazelib not supporting 3.12
+pip install "popgym[navigation]" 
+# Install memory baselines w/ RLlib 
+pip install "popgym[baselines]" 
+```
+
+## Quickstart Usage
+
+```python
+import popgym
+from popgym.wrappers import PreviousAction, Antialias, Flatten, DiscreteAction
+env = popgym.envs.position_only_cartpole.PositionOnlyCartPoleEasy()
+print(env.reset(seed=0))
+wrapped = DiscreteAction(Flatten(PreviousAction(env))) # Append prev action to obs, flatten obs/action spaces, then map the multidiscrete action space to a single discrete action for Q learning
+print(wrapped.reset(seed=0))
 ```
 
 ## POPGym Environments

popgym/envs/__init__.py

@@ -2,7 +2,7 @@
 """
 
 import inspect
-from importlib import find_loader
+from importlib.util import find_spec
 from typing import Any, Dict
 
 import gymnasium as gym
@@ -255,7 +255,7 @@
 #
 def has_mazelib():  # noqa: E302
     """Check if mazelib is installed"""
-    return find_loader("mazelib") is not None
+    return find_spec("mazelib") is not None
 
 
 if has_mazelib():

setup.cfg

@@ -4,7 +4,7 @@ description = A collection of partially-observable procedural gym environments
 long_description = file: README.md
 long_description_content_type = text/markdown
 author = Steven Morad
-version = 1.0.4
+version = 1.0.5
 license = MIT
 readme = README.md
 requires_python = >=3.7