Fix python version subset check

news/66.bugfix

+Regard `4.0` as infinite upper bound when checking subsetting.

news/67.feature

+Display all availible Python interpreters if users don't give on in `pdm init`.

pdm/cli/actions.py

@@ -447,7 +447,7 @@ def do_use(project: Project, python: str, first: bool = False) -> None:
     """Use the specified python version and save in project config.
     The python can be a version string or interpreter path.
     """
-    if not all(c.isdigit() for c in python.split(".")):
+    if python and not all(c.isdigit() for c in python.split(".")):
         if Path(python).exists():
             python_path = Path(python).absolute().as_posix()
         else:
@@ -458,7 +458,7 @@ def do_use(project: Project, python: str, first: bool = False) -> None:
     else:
         finder = pythonfinder.Finder()
         pythons = []
-        args = [int(v) for v in python.split(".")]
+        args = [int(v) for v in python.split(".") if v != ""]
         for i, entry in enumerate(finder.find_all_python_versions(*args)):
             python_version = get_python_version(entry.path.as_posix(), True)
             pythons.append((entry.path.as_posix(), python_version))

pdm/cli/commands.py

@@ -289,7 +289,9 @@ def build(project, sdist, wheel, dest, clean):
 @pass_project
 def init(project):
     """Initialize a pyproject.toml for PDM."""
-    python = click.prompt("Please enter the Python interpreter to use")
+    python = click.prompt(
+        "Please enter the Python interpreter to use", default="", show_default=False
+    )
     actions.do_use(project, python)
 
     if project.pyproject_file.exists():

pdm/models/specifiers.py

@@ -86,6 +86,7 @@ class PySpecSet(SpecifierSet):
         (3, 6): 10,
         (3, 7): 6,
     }
+    MAX_MAJOR_VERSION = 4
     MIN_VERSION = (-1, -1, -1)
     MAX_VERSION = (99, 99, 99)
 
@@ -381,6 +382,10 @@ class PySpecSet(SpecifierSet):
         if self.is_allow_all:
             return True
         other = type(self)(str(other))
+        if other._upper_bound[0] >= self.MAX_MAJOR_VERSION:
+            # XXX: narrow down the upper bound to ``MAX_MAJOR_VERSION``
+            # So that `>=3.6,<4.0` is considered a superset of `>=3.7`, see issues/66
+            other._upper_bound = (self.MAX_MAJOR_VERSION, 0, 0)
         if (
             self._lower_bound > other._lower_bound
             or self._upper_bound < other._upper_bound
@@ -398,6 +403,8 @@ class PySpecSet(SpecifierSet):
         if self.is_impossible:
             return False
         other = type(self)(str(other))
+        if other._upper_bound[0] >= self.MAX_MAJOR_VERSION:
+            other._upper_bound = self.MAX_VERSION
         if other.is_allow_all:
             return True
         if (

tests/resolver/test_resolve.py

@@ -200,3 +200,9 @@ def test_resolve_two_extras_from_the_same_package(project, repository):
     result = resolve_requirements(repository, [line])
     assert "pysocks" in result
     assert "pyopenssl" in result
+
+
+def test_resolve_package_with_dummy_upbound(project, repository):
+    repository.add_candidate("foo", "0.1.0", ">=3.6,<4.0")
+    result = resolve_requirements(repository, ["foo"], ">=3.5")
+    assert "foo" in result