Use pip resolver for version resolution

- Addresses conflicts between the PyPI api and pip
- Fixes #499 
- Uses semantic versioning and PEP approved post-release naming

Pipfile.lock

@@ -5,16 +5,16 @@
         },
         "host-environment-markers": {
             "implementation_name": "cpython",
-            "implementation_version": "3.6.2",
+            "implementation_version": "3.6.1",
             "os_name": "posix",
             "platform_machine": "x86_64",
             "platform_python_implementation": "CPython",
-            "platform_release": "16.7.0",
-            "platform_system": "Darwin",
-            "platform_version": "Darwin Kernel Version 16.7.0: Thu Jun 15 17:36:27 PDT 2017; root:xnu-3789.70.16~2/RELEASE_X86_64",
-            "python_full_version": "3.6.2",
+            "platform_release": "4.10.0-33-generic",
+            "platform_system": "Linux",
+            "platform_version": "#37-Ubuntu SMP Fri Aug 11 10:55:28 UTC 2017",
+            "python_full_version": "3.6.1",
             "python_version": "3.6",
-            "sys_platform": "darwin"
+            "sys_platform": "linux"
         },
         "pipfile-spec": 2,
         "requires": {
@@ -57,8 +57,10 @@
             "version": "==2.0.1"
         },
         "ibm-db-sa-py3": {
-            "hashes": [],
-            "version": "==0.3.1-1"
+            "hashes": [
+                "sha256:c7d50cc3a8ef9e393c35af01d478a05438159a8c2304bf871e3d5eeb43fb97b2"
+            ],
+            "version": "==0.3.1.post1"
         },
         "idna": {
             "hashes": [
@@ -90,10 +92,10 @@
         },
         "pipenv": {
             "hashes": [
-                "sha256:ca20bb3fb6613b6e59f3dc8a94ad00336b4ac94af8b6df59a0539db8fdf0bd9c",
-                "sha256:e2162f30654cf1117900147fb4606199d29f281aee46f80d50ae287134c902ad"
+                "sha256:ee9a152341aa7eceec65f69310b42f14094ed1cacdf1d143b075d290ef3e8f0d",
+                "sha256:37ac7d6576feaa1f85af58df2a3409195977dcdf1ac86462edc4537ca883f181"
             ],
-            "version": "==6.0.3"
+            "version": "==6.1.6"
         },
         "py": {
             "hashes": [

pipenv/utils.py

@@ -27,7 +27,7 @@ def shellquote(s):
 
 
 def clean_pkg_version(version):
-    return six.u(pep440_version(str(version))).replace('==', '')
+    return six.u(pep440_version(str(version).replace('==', '')))
 
 
 def resolve_deps(deps, sources=None, verbose=False, hashes=False):
@@ -69,14 +69,19 @@ def resolve_deps(deps, sources=None, verbose=False, hashes=False):
             try:
                 collected_hashes = []
                 r = requests.get('https://pypi.org/pypi/{0}/json'.format(name))
-                for release in r.json()['releases'][version]:
+                api_releases = r.json()['releases']
+                cleaned_releases = {}
+                for api_version, api_info in api_releases.items():
+                    cleaned_releases[clean_pkg_version(api_version)] = api_info
+    
+                for release in cleaned_releases[version]:
                     collected_hashes.append(release['digests']['sha256'])
 
                 collected_hashes = ['sha256:' + s for s in collected_hashes]
 
                 # Collect un-collectable hashes.
                 if not collected_hashes:
-                    collected_hashes = list(resolver.resolve_hashes([result]).items()[0][1])
+                    collected_hashes = list(list(resolver.resolve_hashes([result]).items())[0][1])
 
                 results.append({'name': name, 'version': version, 'hashes': collected_hashes})
             except ValueError:
@@ -254,8 +259,8 @@ def is_vcs(pipfile_entry):
 
 
 def pep440_version(version):
-    # TODO: https://github.com/pypa/pip/blob/a9d56c7734fd465d01437d61f632749a293e7805/src/pip/_vendor/distlib/version.py#L184
-    return version.replace('.post', '-')
+    # use pip built in version parser
+    return str(pip.index.parse_version(version))
 
 
 def pep423_name(name):

tests/test_pipenv.py

@@ -42,6 +42,7 @@ class TestPipenv():
         assert delegator.run('pipenv --python python').return_code == 0
         assert delegator.run('pipenv install Werkzeug').return_code == 0
         assert delegator.run('pipenv install pytest --dev').return_code == 0
+        assert delegator.run('pipenv install regex').return_code == 0 # failing before
         assert delegator.run('pipenv install git+https://github.com/requests/requests.git@v2.18.4#egg=requests').return_code == 0
         assert delegator.run('pipenv lock').return_code == 0