Handle unspecified python versioning on Pipfile

Author: sanspareilsmyn

news/6164.bugfix.rst

@@ -0,0 +1 @@
+Pipenv only supports absolute python version. If the user specifies a Python version with inequality signs like >=3.12, <3.12 in the [requires] field, the code has been modified to explicitly express in an error log that absolute versioning must be used.

pipenv/utils/virtualenv.py

@@ -1,5 +1,6 @@
 import contextlib
 import os
+import re
 import shutil
 import sys
 from pathlib import Path
@@ -237,6 +238,22 @@ def abort(msg=""):
     # Find out which python is desired.
     if not python:
         python = project.required_python_version
+        if python:
+            range_pattern = r"^[<>]=?|!="
+            if re.search(range_pattern, python):
+                click.echo(
+                    "{}: Python version range specifier '{}' is not supported. {}".format(
+                        click.style("Error", fg="red", bold=True),
+                        click.style(python, fg="cyan"),
+                        click.style(
+                            "Please use an absolute version number or specify the path to the Python executable on Pipfile.",
+                            fg="yellow",
+                        ),
+                    ),
+                    err=True,
+                )
+                abort()
+
     if not python:
         python = project.s.PIPENV_DEFAULT_PYTHON_VERSION
     path_to_python = find_a_system_python(python)

tests/integration/test_install_basic.py

@@ -403,6 +403,64 @@ def test_create_pipfile_requires_python_full_version(pipenv_instance_private_pyp
             'python_version': python_version
             }
 
+@pytest.mark.basic
+@pytest.mark.install
+@pytest.mark.virtualenv
+def test_install_with_pipfile_including_exact_python_version(pipenv_instance_pypi):
+    valid_version = f"{sys.version_info.major}.{sys.version_info.minor}"
+
+    with pipenv_instance_pypi() as p:
+        with open(p.pipfile_path, 'w') as f:
+            f.write(f"""
+[[source]]
+url = "https://test.pypi.org/simple"
+verify_ssl = true
+name = "testpypi"
+
+[packages]
+pytz = "*"
+
+[requires]
+python_version = "{valid_version}"
+""")
+
+        c = p.pipenv("install")
+        assert c.returncode == 0
+        assert os.path.isfile(p.pipfile_path)
+        assert p.pipfile["requires"]["python_version"] == valid_version
+
+        c = p.pipenv("--rm")
+        assert c.returncode == 0
+
+@pytest.mark.basic
+@pytest.mark.install
+@pytest.mark.virtualenv
+def test_install_with_pipfile_including_invalid_python_version(pipenv_instance_pypi):
+    invalid_versions = [
+        f">={sys.version_info.major}.{sys.version_info.minor}",
+        f"<={sys.version_info.major}.{sys.version_info.minor}",
+        f">{sys.version_info.major}.{sys.version_info.minor}",
+        f"<{sys.version_info.major}.{sys.version_info.minor}",
+    ]
+
+    with pipenv_instance_pypi() as p:
+        for version in invalid_versions:
+            with open(p.pipfile_path, 'w') as f:
+                f.write(f"""
+[[source]]
+url = "https://test.pypi.org/simple"
+verify_ssl = true
+name = "testpypi"
+
+[packages]
+pytz = "*"
+
+[requires]
+python_version = "{version}"
+""")
+            c = p.pipenv("install --verbose")
+            assert c.returncode != 0
+
 
 @pytest.mark.basic
 @pytest.mark.install