Use a helper function to get the requirement key

Change-Id: I05a3a664570a7ce058e3efda3089a56886ee59ce

tools/multipip

@@ -345,6 +345,10 @@ def parse_requirements(options):
 
     :return: tuple (all, ignored) of InstallRequirement
     """
+
+    def req_key(req):
+        return req.req.key
+
     all_requirements = {}
     skip_match = None
     if options.skip_requirements_regex:
@@ -352,18 +356,18 @@ def parse_requirements(options):
     for req_spec in options.requirement_specs:
         try:
             req = install_requirement_parse(req_spec, "command line")
-            if skip_match and skip_match.search(req.req.key):
+            if skip_match and skip_match.search(req_key(req)):
                 continue
-            all_requirements.setdefault(req.req.key, []).append(req)
+            all_requirements.setdefault(req_key(req), []).append(req)
         except Exception as ex:
             raise RequirementException("Cannot parse `%s': %s" % (req_spec, ex))
     for filename in options.requirements:
         try:
             for req in pip.req.parse_requirements(filename):
                 req = install_requirement_ensure_req_field(req)
-                if skip_match and skip_match.search(req.req.key):
+                if skip_match and skip_match.search(req_key(req)):
                     continue
-                all_requirements.setdefault(req.req.key, []).append(req)
+                all_requirements.setdefault(req_key(req), []).append(req)
         except Exception as ex:
             raise RequirementException("Cannot parse `%s': %s" % (filename, ex))
     ignored_requirements = []