Removed dangling print and added disable_print parameter (#137)

Co-authored-by: Mark Towers <mark.m.towers@gmail.com>

docs/api/registry.md

@@ -21,7 +21,7 @@ Environments can also be created through python imports.
 
 ## All registered environments
 
-To find all the registered Gymnasium environments, use the `gymnasium.envs.registry.keys()`.
+To find all the registered Gymnasium environments, use the `gymnasium.pprint_registry()`.
 This will not include environments registered only in OpenAI Gym however can be loaded by `gymnasium.make`.
 
 ## Spec
@@ -29,3 +29,10 @@ This will not include environments registered only in OpenAI Gym however can be
 ```{eval-rst}
 .. autofunction:: gymnasium.spec
 ```
+
+
+## Pretty print registry
+
+```{eval-rst}
+.. autofunction:: gymnasium.pprint_registry
+```

docs/conf.py

@@ -60,6 +60,7 @@ napoleon_custom_sections = [("Returns", "params_style")]
 
 # Autodoc
 autoclass_content = "both"
+autodoc_preserve_defaults = True
 
 # -- Options for HTML output -------------------------------------------------
 

docs/requirements.txt

@@ -1,4 +1,5 @@
 sphinx
+sphinx-autobuild
 myst-parser
 sphinx_gallery
 git+https://github.com/Farama-Foundation/Celshast#egg=furo

gymnasium/envs/registration.py

@@ -708,15 +708,23 @@ def pprint_registry(
     _registry: dict = registry,
     max_rows: int = 10,
     exclude_namespaces: Optional[List[str]] = None,
-) -> None:
-    """List the environments currently supported."""
+    disable_print: bool = False,
+) -> Optional[str]:
+    """Pretty print the environments in the registry.
+
+    Args:
+        _registry: Environment registry to be printed.
+        max_rows: Number of rows per column.
+        exclude_namespaces: Exclude any namespaces from being printed.
+        disable_print: Whether to return a string of all the namespaces and environment IDs
+            instead of printing it to console.
+    """
 
     # Defaultdict to store environment names according to namespace.
     namespace_envs = defaultdict(lambda: [])
     max_justify = float("-inf")
     for env in _registry.values():
         namespace, _, _ = parse_env_id(env.id)
-        print(namespace, env.id, env.entry_point)
         if namespace is None:
             # Since namespace is currently none, use regex to obtain namespace from entrypoints.
             env_entry_point = re.sub(r":\w+", "", env.entry_point)
@@ -756,4 +764,7 @@ def pprint_registry(
                 return_str += "\n"
         return_str += "\n"
 
-    return return_str
+    if disable_print:
+        return return_str
+    else:
+        print(return_str, end="")

tests/envs/test_pprint_registry.py

@@ -10,20 +10,19 @@ def test_pprint_custom_registry():
         "CartPole-v0": gym.envs.registry["CartPole-v0"],
         "CartPole-v1": gym.envs.registry["CartPole-v1"],
     }
-    out = gym.pprint_registry(a)
+    out = gym.pprint_registry(a, disable_print=True)
 
     correct_out = """===== classic_control =====
 CartPole-v0 
 CartPole-v1 
 
 """
-
     assert out == correct_out
 
 
 def test_pprint_registry():
     """Testing the default registry, with no changes."""
-    out = gym.pprint_registry()
+    out = gym.pprint_registry(disable_print=True)
 
     correct_out = """===== classic_control =====
 Acrobot-v1                   
@@ -79,8 +78,7 @@ test/NoHumanOldAPI-v0
 def test_pprint_registry_exclude_namespaces():
     """Testing the default registry, with no changes."""
     out = gym.pprint_registry(
-        max_rows=20,
-        exclude_namespaces=["classic_control"],
+        max_rows=20, exclude_namespaces=["classic_control"], disable_print=True
     )
 
     correct_out = """===== box2d =====
@@ -134,7 +132,7 @@ def test_pprint_registry_no_entry_point():
     """Test registry if there is environment with no entry point."""
 
     gym.register("NoNamespaceEnv", "no-entry-point")
-    out = gym.pprint_registry()
+    out = gym.pprint_registry(disable_print=True)
 
     correct_out = """===== classic_control =====
 Acrobot-v1