Fix Dependency.to_pep_508() method

poetry/packages/dependency.py

@@ -107,11 +107,11 @@ class Dependency:
         requirement = f'{self.pretty_name}'
 
         if isinstance(self.constraint, MultiConstraint):
-            requirement += ','.join(
+            requirement += ' ({})'.format(','.join(
                 [str(c).replace(' ', '') for c in self.constraint.constraints]
-            )
+            ))
         else:
-            requirement += str(self.constraint).replace(' ', '')
+            requirement += ' ({})'.format(str(self.constraint).replace(' ', ''))
 
         # Markers
         markers = []
@@ -119,21 +119,31 @@ class Dependency:
         # Python marker
         if self.python_versions != '*':
             python_constraint = self.python_constraint
-            marker = 'python_version'
-            if isinstance(python_constraint, MultiConstraint):
-                marker += ','.join(
-                    [str(c).replace(' ', '') for c in python_constraint.constraints]
-                )
-            else:
-                marker += str(python_constraint).replace(' ', '')
 
-            markers.append(marker)
+            markers.append(self._create_nested_marker('python_version', python_constraint))
 
         if markers:
             requirement += f'; {" and ".join(markers)}'
 
         return requirement
 
+    def _create_nested_marker(self, name, constraint):
+        if isinstance(constraint, MultiConstraint):
+            parts = []
+            for c in constraint.constraints:
+                parts.append(self._create_nested_marker(name, c))
+
+            glue = ' and '
+            if constraint.is_disjunctive():
+                parts = [f'({part})' for part in parts]
+                glue = ' or '
+
+            marker = glue.join(parts)
+        else:
+            marker = f'{name}{constraint.string_operator}"{constraint.version}"'
+
+        return marker
+
     def activate(self):
         """
         Set the dependency as mandatory.

poetry/semver/constraints/constraint.py

@@ -42,6 +42,7 @@ class Constraint(BaseConstraint):
             )
 
         self._operator = self._trans_op_str[operator]
+        self._string_operator = operator
         self._version = version
         
     @property
@@ -53,6 +54,10 @@ class Constraint(BaseConstraint):
         return self._operator
 
     @property
+    def string_operator(self):
+        return self._string_operator
+
+    @property
     def version(self) -> str:
         return self._version
 

tests/masonry/builders/test_sdist.py

@@ -39,9 +39,9 @@ def test_convert_dependencies():
         get_dependency('C', '1.2.3'),
     ])
     main = [
-        'A>=1.0.0.0,<2.0.0.0',
-        'B>=1.0.0.0,<1.1.0.0',
-        'C==1.2.3.0',
+        'A (>=1.0.0.0,<2.0.0.0)',
+        'B (>=1.0.0.0,<1.1.0.0)',
+        'C (==1.2.3.0)',
     ]
     extras = []
 
@@ -56,11 +56,11 @@ def test_convert_dependencies():
         get_dependency('C', '1.2.3'),
     ])
     main = [
-        'B>=1.0.0.0,<1.1.0.0',
-        'C==1.2.3.0',
+        'B (>=1.0.0.0,<1.1.0.0)',
+        'C (==1.2.3.0)',
     ]
     extras = [
-        'A>=1.0.0.0,<2.0.0.0; python_version>=3.4.0.0,<4.0.0.0',
+        'A (>=1.0.0.0,<2.0.0.0); python_version>="3.4.0.0" and python_version<"4.0.0.0"',
     ]
 
     assert result == (main, extras)
@@ -82,7 +82,7 @@ def test_make_setup():
         'my_package.sub_pkg2'
     ]
     assert ns['install_requires'] == [
-        'cleo>=0.6.0.0,<0.7.0.0'
+        'cleo (>=0.6.0.0,<0.7.0.0)'
     ]
     assert ns['entry_points'] == {
         'console_scripts': ['my-script = my_package:main']

tests/packages/test_dependency.py

@@ -53,3 +53,18 @@ def test_accepts_fails_with_python_versions_mismatch():
     package.python_versions = '~3.5'
 
     assert not dependency.accepts(package)
+
+
+def test_to_pep_508():
+    dependency = Dependency('Django', '^1.23')
+
+    result = dependency.to_pep_508()
+    assert result == 'Django (>=1.23.0.0,<2.0.0.0)'
+
+    dependency = Dependency('Django', '^1.23')
+    dependency.python_versions = '~2.7 || ^3.6'
+
+    result = dependency.to_pep_508()
+    assert result == 'Django (>=1.23.0.0,<2.0.0.0); ' \
+                     '(python_version>="2.7.0.0" and python_version<"2.8.0.0") ' \
+                     'or (python_version>="3.6.0.0" and python_version<"4.0.0.0")'