Fix handling of single versions when packaging

CHANGELOG.md

@@ -6,10 +6,10 @@
 
 - Poetry now only uses [TOML Kit](https://github.com/sdispater/tomlkit) for TOML files manipulation.
 
-
 ### Fixed
 
 - Fixed missing dependency information for some packages.
+- Fixed handling of single versions when packaging.
 
 
 ## [0.11.2] - 2018-07-03

poetry/semver/version.py

@@ -23,7 +23,7 @@ class Version(VersionRange):
         pre=None,  # type: Union[str, None]
         build=None,  # type: Union[str, None]
         text=None,  # type: Union[str, None]
-        precision=None,  # type: Union[str, None]
+        precision=None,  # type: Union[int, None]
     ):  # type: () -> None
         self._major = int(major)
         self._precision = None
@@ -106,6 +106,10 @@ class Version(VersionRange):
         return self._text
 
     @property
+    def precision(self):  # type: () -> int
+        return self._precision
+
+    @property
     def stable(self):
         if not self.is_prerelease():
             return self

poetry/version/helpers.py

 from poetry.semver import parse_constraint
+from poetry.semver import Version
 from poetry.semver import VersionUnion
 
 PYTHON_VERSION = [
@@ -20,6 +21,16 @@ def format_python_constraint(constraint):
     This helper will help in transforming
     disjunctive constraint into proper constraint.
     """
+    if isinstance(constraint, Version) and constraint.precision < 3:
+        # Transform 3.6 or 3
+        if constraint.precision == 2:
+            # 3.6
+            constraint = parse_constraint(
+                "~{}.{}".format(constraint.major, constraint.minor)
+            )
+        else:
+            constraint = parse_constraint("^{}.0".format(constraint.major))
+
     if not isinstance(constraint, VersionUnion):
         return str(constraint)
 

tests/masonry/builders/fixtures/simple_version/README.rst

+Module 1
+========

tests/masonry/builders/fixtures/simple_version/pyproject.toml

+[tool.poetry]
+name = "simple-version"
+version = "0.1"
+description = "Some description."
+authors = [
+    "Sébastien Eustace <sebastien@eustace.io>"
+]
+license = "MIT"
+
+readme = "README.rst"
+
+homepage = "https://poetry.eustace.io/"
+
+
+[tool.poetry.dependencies]
+python = "3.6"

tests/masonry/builders/fixtures/simple_version/simple_version.py

+"""Example module"""
+
+__version__ = "0.1"

tests/masonry/builders/test_sdist.py

@@ -395,3 +395,14 @@ def test_package_with_include(mocker):
     assert "with-include-1.2.3/pyproject.toml" in names
     assert "with-include-1.2.3/setup.py" in names
     assert "with-include-1.2.3/PKG-INFO" in names
+
+
+def test_proper_python_requires_if_single_version_specified():
+    poetry = Poetry.create(project("simple_version"))
+
+    builder = SdistBuilder(poetry, NullVenv(), NullIO())
+    pkg_info = builder.build_pkg_info()
+    p = Parser()
+    parsed = p.parsestr(to_str(pkg_info))
+
+    assert parsed["Requires-Python"] == ">=3.6,<3.7"

tests/version/test_helpers.py

@@ -8,3 +8,17 @@ def test_format_python_constraint():
     result = format_python_constraint(constraint)
 
     assert result == ">=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*, !=3.4.*, !=3.5.*"
+
+
+def test_format_python_constraint_single_version():
+    constraint = parse_constraint("3.6")
+
+    result = format_python_constraint(constraint)
+
+    assert result == ">=3.6,<3.7"
+
+    constraint = parse_constraint("3")
+
+    result = format_python_constraint(constraint)
+
+    assert result == ">=3.0,<4.0"