Adopt the use of OrderedDict (#4650)

pip/req/__init__.py

@@ -1,10 +1,10 @@
 from __future__ import absolute_import
 
 from .req_install import InstallRequirement
-from .req_set import RequirementSet, Requirements
+from .req_set import RequirementSet
 from .req_file import parse_requirements
 
 __all__ = [
-    "RequirementSet", "Requirements", "InstallRequirement",
+    "RequirementSet", "InstallRequirement",
     "parse_requirements",
 ]

pip/req/req_set.py

@@ -1,7 +1,7 @@
 from __future__ import absolute_import
 
 import logging
-from collections import defaultdict
+from collections import OrderedDict, defaultdict
 
 from pip.exceptions import InstallationError
 from pip.utils.logging import indent_log
@@ -10,34 +10,6 @@
 logger = logging.getLogger(__name__)
 
 
-class Requirements(object):
-
-    def __init__(self):
-        self._keys = []
-        self._dict = {}
-
-    def keys(self):
-        return self._keys
-
-    def values(self):
-        return [self._dict[key] for key in self._keys]
-
-    def __contains__(self, item):
-        return item in self._keys
-
-    def __setitem__(self, key, value):
-        if key not in self._keys:
-            self._keys.append(key)
-        self._dict[key] = value
-
-    def __getitem__(self, key):
-        return self._dict[key]
-
-    def __repr__(self):
-        values = ['%s: %s' % (repr(k), repr(self[k])) for k in self.keys()]
-        return 'Requirements({%s})' % ', '.join(values)
-
-
 class RequirementSet(object):
 
     def __init__(self,
@@ -49,8 +21,7 @@ def __init__(self,
             InstallRequirement.
         """
 
-        self.requirements = Requirements()
-
+        self.requirements = OrderedDict()
         self.require_hashes = require_hashes
 
         # Mapping of alias: real_name

pip/resolve.py

@@ -75,7 +75,7 @@ def resolve(self, requirement_set):
         # hash-checking mode, which requires hashes from all.
         root_reqs = (
             requirement_set.unnamed_requirements +
-            requirement_set.requirements.values()
+            list(requirement_set.requirements.values())
         )
         self.require_hashes = (
             requirement_set.require_hashes or

tests/unit/test_req.py

@@ -16,7 +16,7 @@
 )
 from pip.index import PackageFinder
 from pip.operations.prepare import RequirementPreparer
-from pip.req import InstallRequirement, Requirements, RequirementSet
+from pip.req import InstallRequirement, RequirementSet
 from pip.req.req_file import process_line
 from pip.req.req_install import parse_editable
 from pip.resolve import Resolver
@@ -547,32 +547,6 @@ def test_requirement_file(self):
         assert "If that is the case, use the '-r' flag to install" in err_msg
 
 
-def test_requirements_data_structure_keeps_order():
-    requirements = Requirements()
-    requirements['pip'] = 'pip'
-    requirements['nose'] = 'nose'
-    requirements['coverage'] = 'coverage'
-
-    assert ['pip', 'nose', 'coverage'] == list(requirements.values())
-    assert ['pip', 'nose', 'coverage'] == list(requirements.keys())
-
-
-def test_requirements_data_structure_implements__repr__():
-    requirements = Requirements()
-    requirements['pip'] = 'pip'
-    requirements['nose'] = 'nose'
-
-    assert "Requirements({'pip': 'pip', 'nose': 'nose'})" == repr(requirements)
-
-
-def test_requirements_data_structure_implements__contains__():
-    requirements = Requirements()
-    requirements['pip'] = 'pip'
-
-    assert 'pip' in requirements
-    assert 'nose' not in requirements
-
-
 @patch('pip.req.req_install.os.path.abspath')
 @patch('pip.req.req_install.os.path.exists')
 @patch('pip.req.req_install.os.path.isdir')