✨ Implemented #14

idae/cli.py

@@ -1,4 +1,5 @@
 """CLI interface."""
+
 import itertools
 import platform
 import shlex
@@ -52,7 +53,6 @@ def run(  # noqa: PLR0913
     ignore_version: Annotated[
         bool,
         typer.Option(
-            "--ignore-version",
             "-i",
             help="Ignore Python version requirements specified in the script",
         ),
@@ -71,6 +71,14 @@ def run(  # noqa: PLR0913
             help="Force idae to use a specific Python version",
         ),
     ] = None,
+    use_latest: Annotated[
+        bool,
+        typer.Option(
+            "-l",
+            help="Use the latest Python version that satisfies the "
+            "script's requirements",
+        ),
+    ] = False,
 ) -> None:
     """Automatically install necessary dependencies to run a Python script.
 
@@ -93,7 +101,7 @@ def run(  # noqa: PLR0913
         executable=sys.executable,
     )
     if force_version is not None:
-        python = get_python_or_exit(force_version, console)
+        python = get_python_or_exit(force_version, console, use_latest)
     if pyproject is not None:
         script_deps = (
             []

idae/resolver.py

@@ -10,12 +10,15 @@
 
 if TYPE_CHECKING:  # pragma: no cover
     from rich.console import Console
+from .venv import is_python_cached
 
 
-def get_python_or_exit(version: str, console: Console) -> findpython.PythonVersion:
+def get_python_or_exit(
+    version: str, console: Console, use_latest: bool,
+) -> findpython.PythonVersion:
     """Return a PythonVersion or raise Exit."""
     try:
-        output = get_python(version)
+        output = get_python(version, use_latest)
     except InvalidSpecifier as err:
         console.print(f"[red]error: Python version {version} could not be parsed[/red]")
         raise typer.Exit(code=1) from err
@@ -25,7 +28,7 @@ def get_python_or_exit(version: str, console: Console) -> findpython.PythonVersi
     return output
 
 
-def get_python(version: str) -> findpython.PythonVersion | None:
+def get_python(version: str, use_latest: bool) -> findpython.PythonVersion | None:
     """Resolve the version string and return a valid Python."""
     # Order from latest version to earliest
     pythons = {python.version: python for python in findpython.find_all()}
@@ -36,7 +39,14 @@ def get_python(version: str) -> findpython.PythonVersion | None:
     else:
         version = f"~={float(version)}"
     target = SpecifierSet(version)
+    cached_candidates = None
+    uncached_candidates = None
     for python_version, python in pythons.items():
         if python_version in target:
-            return python
-    return None
+            if use_latest:
+                return python
+            if is_python_cached(python.version) and cached_candidates is None:
+                cached_candidates = python
+            elif uncached_candidates is None:
+                uncached_candidates = python
+    return cached_candidates or uncached_candidates

idae/venv.py

@@ -1,4 +1,5 @@
 """Utils for venv creation."""
+
 from __future__ import annotations
 
 import platform
@@ -29,6 +30,11 @@ class Python:
     executable: str | PathLike[str]
 
 
+def is_python_cached(python: str) -> bool:
+    """Check if a Python version is cached."""
+    return (CACHE_DIR / f"{python.version.major}.{python.version.minor}").is_dir()
+
+
 def get_venv(requirements: list[Requirement], python: Python) -> Path:
     """Create or fetch a cached venv."""
     dep_hash = hash_dependencies(requirements)