Improved the jsonargparse[signatures] availability variable

pytorch_lightning/utilities/cli.py

@@ -29,13 +29,13 @@
 from pytorch_lightning import Callback, LightningDataModule, LightningModule, seed_everything, Trainer
 from pytorch_lightning.utilities.cloud_io import get_filesystem
 from pytorch_lightning.utilities.exceptions import MisconfigurationException
-from pytorch_lightning.utilities.imports import _RequirementAvaliable
+from pytorch_lightning.utilities.imports import _RequirementAvailable
 from pytorch_lightning.utilities.meta import get_all_subclasses
 from pytorch_lightning.utilities.model_helpers import is_overridden
 from pytorch_lightning.utilities.rank_zero import _warn, rank_zero_deprecation, rank_zero_warn
 from pytorch_lightning.utilities.seed import _select_seed_randomly
 
-_JSONARGPARSE_SIGNATURES_AVAILABLE = _RequirementAvaliable("jsonargparse[signatures]>=4.7.1")
+_JSONARGPARSE_SIGNATURES_AVAILABLE = _RequirementAvailable("jsonargparse[signatures]>=4.7.1")
 
 if _JSONARGPARSE_SIGNATURES_AVAILABLE:
     import docstring_parser

pytorch_lightning/utilities/imports.py

@@ -85,24 +85,44 @@ def _compare_version(package: str, op: Callable, version: str, use_base_version:
     return op(pkg_version, Version(version))
 
 
-class _RequirementAvaliable:
-    """Boolean-like class for check of requirement with extras and version specifiers."""
-
-    def __init__(self, requirement: str):
-        self.available = True
-        self.message = ""
-        try:
-            pkg_resources.require([requirement])
-        except Exception as ex:
-            self.available = False
-            self.message = f"Requirement '{requirement}' not met, {ex.__class__.__name__}: {ex}"
+class _RequirementAvailable:
+    """Boolean-like class for check of requirement with extras and version specifiers.
+
+    >>> _RequirementAvailable("jsonargparse[signatures]>=4.7.3")
+    Requirement 'jsonargparse[signatures]>=4.7.3' not met, VersionConflict: (jsonargparse 4.7.2 ..., Requirement.parse('jsonargparse[signatures]>=4.7.3'))
+    >>> bool(_RequirementAvailable("jsonargparse[signatures]>=4.7.3"))
+    False
+    >>> bool(_RequirementAvailable("jsonargparse[signatures]>=4.7.2"))
+    True
+    """
+
+    def __init__(self, requirement: str) -> None:
+        self.available = None
+        self.requirement = requirement
+        self.__repr__ = self.__str__
+
+    def _check_requirement(self) -> None:
+        if self.available is None:
+            try:
+                pkg_resources.require([self.requirement])
+            except Exception as ex:
+                self.available = False
+                self.message = f"Requirement {self.requirement!r} not met, {ex.__class__.__name__}: {ex}"
+            else:
+                self.available = True
+                self.message = f"Requirement {self.requirement!r} met"
 
     def __bool__(self) -> bool:
+        self._check_requirement()
         return self.available
 
     def __str__(self) -> str:
+        self._check_requirement()
         return self.message
 
+    def __repr__(self) -> str:
+        return self.__str__()
+
 
 _IS_WINDOWS = platform.system() == "Windows"
 _IS_INTERACTIVE = hasattr(sys, "ps1")  # https://stackoverflow.com/a/64523765

tests/utilities/test_imports.py

@@ -23,7 +23,7 @@
     _OMEGACONF_AVAILABLE,
     _POPTORCH_AVAILABLE,
 )
-from pytorch_lightning.utilities.imports import _compare_version, _RequirementAvaliable, torch
+from pytorch_lightning.utilities.imports import _compare_version, _RequirementAvailable, torch
 
 
 def test_module_exists():
@@ -55,9 +55,9 @@ def test_compare_version(monkeypatch):
 
 
 def test_requirement_avaliable():
-    assert _RequirementAvaliable(f"torch>={torch.__version__}")
-    assert not _RequirementAvaliable(f"torch<{torch.__version__}")
-    assert "Requirement '-' not met" in str(_RequirementAvaliable("-"))
+    assert _RequirementAvailable(f"torch>={torch.__version__}")
+    assert not _RequirementAvailable(f"torch<{torch.__version__}")
+    assert "Requirement '-' not met" in str(_RequirementAvailable("-"))
 
 
 def test_imports():