diff --git a/README.md b/README.md
index 0a0540a17e..03bcf0b3ee 100644
--- a/README.md
+++ b/README.md
@@ -97,8 +97,16 @@ load("@rules_python//python:pip.bzl", "pip_import")
 # This rule translates the specified requirements.txt into
 # @my_deps//:requirements.bzl, which itself exposes a pip_install method.
 pip_import(
-   name = "my_deps",
-   requirements = "//path/to:requirements.txt",
+  name = "my_deps",
+  requirements = "//path/to:requirements.txt",
+)
+
+# Python interpreter can be specify optionally to support customized version,
+# such as "python3" or "python3.7"
+pip_import(
+  name = "my_deps",
+  requirements = "//path/to:requirements.txt",
+  python_interpreter = 'python3.7',
 )
 
 # Load the pip_install symbol for my_deps, and create the dependencies'
diff --git a/packaging/piptool.py b/packaging/piptool.py
index 2544032ee8..9fef4c7ece 100644
--- a/packaging/piptool.py
+++ b/packaging/piptool.py
@@ -86,6 +86,9 @@ def pip_main(argv):
 parser = argparse.ArgumentParser(
     description='Import Python dependencies into Bazel.')
 
+parser.add_argument('--python_interpreter', action='store',
+                    help=('The python python interpreter to use '))
+
 parser.add_argument('--name', action='store',
                     help=('The namespace of the import.'))
 
@@ -98,6 +101,12 @@ def pip_main(argv):
 parser.add_argument('--directory', action='store',
                     help=('The directory into which to put .whl files.'))
 
+
+def sort_wheels(whls):
+  """Sorts a list of wheels deterministically."""
+  return sorted(whls, key=lambda w: w.distribution() + '_' + w.version())
+
+
 def determine_possible_extras(whls):
   """Determines the list of possible "extras" for each .whl
 
@@ -146,7 +155,7 @@ def is_possible(distro, extra):
   return {
     whl: [
       extra
-      for extra in whl.extras()
+      for extra in sorted(whl.extras())
       if is_possible(whl.distribution(), extra)
     ]
     for whl in whls
@@ -167,7 +176,7 @@ def list_whls():
         if fname.endswith('.whl'):
           yield os.path.join(root, fname)
 
-  whls = [Wheel(path) for path in list_whls()]
+  whls = sort_wheels(Wheel(path) for path in list_whls())
   possible_extras = determine_possible_extras(whls)
 
   def whl_library(wheel):
@@ -177,10 +186,12 @@ def whl_library(wheel):
   if "{repo_name}" not in native.existing_rules():
     whl_library(
         name = "{repo_name}",
+        python_interpreter = "{python_interpreter}",
         whl = "@{name}//:{path}",
         requirements = "@{name}//:requirements.bzl",
         extras = [{extras}]
     )""".format(name=args.name, repo_name=wheel.repository_name(),
+                python_interpreter=args.python_interpreter,
                 path=wheel.basename(),
                 extras=','.join([
                   '"%s"' % extra
diff --git a/packaging/whl.py b/packaging/whl.py
index 63a6d62b8f..7dd8845ea7 100644
--- a/packaging/whl.py
+++ b/packaging/whl.py
@@ -14,11 +14,17 @@
 """The whl modules defines classes for interacting with Python packages."""
 
 import argparse
+import collections
+import email.parser
 import json
 import os
 import pkg_resources
 import re
 import zipfile
+import sys
+
+EXTRA_RE = re.compile("""^(?P<package>.*?)(;\s*(?P<condition>.*?)(extra == '(?P<extra>.*?)')?)$""")
+MayRequiresKey = collections.namedtuple('MayRequiresKey', ('condition', 'extra'))
 
 
 class Wheel(object):
@@ -44,7 +50,7 @@ def version(self):
 
   def repository_name(self):
     # Returns the canonical name of the Bazel repository for this package.
-    canonical = 'pypi__{}_{}'.format(self.distribution(), self.version())
+    canonical = 'pypi__py{}__{}_{}'.format(sys.version_info.major, self.distribution(), self.version())
     # Escape any illegal characters with underscore.
     return re.sub('[-.+]', '_', canonical)
 
@@ -66,7 +72,7 @@ def metadata(self):
           pass
       # fall back to METADATA file (https://www.python.org/dev/peps/pep-0427/)
       with whl.open(self._dist_info() + '/METADATA') as f:
-        return self._parse_metadata(f.read().decode("utf-8"))
+        return self._parse_metadata(f)
 
   def name(self):
     return self.metadata().get('name')
@@ -111,9 +117,48 @@ def expand(self, directory):
 
   # _parse_metadata parses METADATA files according to https://www.python.org/dev/peps/pep-0314/
   def _parse_metadata(self, content):
-    # TODO: handle fields other than just name
-    name_pattern = re.compile('Name: (.*)')
-    return { 'name': name_pattern.search(content).group(1) }
+    metadata = {}
+    content_str = content.read()
+    try:
+      pkg_info = email.parser.Parser().parsestr(content_str)
+    except:
+      pkg_info = email.parser.BytesParser().parsebytes(content_str)
+
+    metadata['name'] = pkg_info.get('Name')
+    extras = pkg_info.get_all('Provides-Extra')
+    if extras:
+      metadata['extras'] = list(set(extras))
+
+    reqs_dist = pkg_info.get_all('Requires-Dist') or []
+    requires = collections.defaultdict(set)
+    for value in sorted(reqs_dist):
+      extra_match = EXTRA_RE.search(value)
+      if extra_match:
+        groupdict = extra_match.groupdict()
+        condition = groupdict['condition']
+        extra = groupdict['extra']
+        package = groupdict['package']
+        if condition.endswith(' and '):
+          condition = condition[:-5]
+      else:
+        condition, extra = None, None
+        package = value
+      key = MayRequiresKey(condition, extra)
+      requires[key].add(package)
+
+    if requires:
+      metadata['run_requires'] = []
+      for key, value in requires.items():
+        requirement = {
+          'requires': list(value)
+        }
+        if key.extra:
+          requirement['extra'] = key.extra
+        if key.condition:
+          requirement['environment'] = key.condition
+        metadata['run_requires'].append(requirement)
+
+    return metadata
 
 
 parser = argparse.ArgumentParser(
diff --git a/python/pip.bzl b/python/pip.bzl
index b69eb9366e..8554386997 100644
--- a/python/pip.bzl
+++ b/python/pip.bzl
@@ -24,8 +24,10 @@ def _pip_import_impl(repository_ctx):
 
     # To see the output, pass: quiet=False
     result = repository_ctx.execute([
-        "python",
+        repository_ctx.attr.python_interpreter,
         repository_ctx.path(repository_ctx.attr._script),
+        "--python_interpreter",
+        repository_ctx.attr.python_interpreter,
         "--name",
         repository_ctx.attr.name,
         "--input",
@@ -34,13 +36,14 @@ def _pip_import_impl(repository_ctx):
         repository_ctx.path("requirements.bzl"),
         "--directory",
         repository_ctx.path(""),
-    ])
+    ], quiet=False)
 
     if result.return_code:
         fail("pip_import failed: %s (%s)" % (result.stdout, result.stderr))
 
 pip_import = repository_rule(
     attrs = {
+        "python_interpreter": attr.string(default="python"),
         "requirements": attr.label(
             mandatory = True,
             allow_single_file = True,
diff --git a/python/whl.bzl b/python/whl.bzl
index 3f869c29ec..2eebfee49f 100644
--- a/python/whl.bzl
+++ b/python/whl.bzl
@@ -17,7 +17,7 @@ def _whl_impl(repository_ctx):
     """Core implementation of whl_library."""
 
     args = [
-        "python",
+        repository_ctx.attr.python_interpreter,
         repository_ctx.path(repository_ctx.attr._script),
         "--whl",
         repository_ctx.path(repository_ctx.attr.whl),
@@ -37,6 +37,7 @@ def _whl_impl(repository_ctx):
 
 whl_library = repository_rule(
     attrs = {
+        "python_interpreter": attr.string(default="python"),
         "whl": attr.label(
             mandatory = True,
             allow_single_file = True,
diff --git a/tools/piptool.par b/tools/piptool.par
index f0e0f224e5..85dff20a2b 100755
Binary files a/tools/piptool.par and b/tools/piptool.par differ
diff --git a/tools/whltool.par b/tools/whltool.par
index c7c0212a1b..3d255ae6f1 100755
Binary files a/tools/whltool.par and b/tools/whltool.par differ