Use format options for abspath

src/pip/_internal/commands/cache.py

@@ -37,18 +37,22 @@ class CacheCommand(Command):
     usage = """
         %prog dir
         %prog info
-        %prog list [<pattern>] [--abspath]
+        %prog list [<pattern>] [--format=[human, abspath]]
         %prog remove <pattern>
         %prog purge
     """
 
     def add_options(self):
         # type: () -> None
+
         self.cmd_opts.add_option(
-            '--abspath',
-            dest='abspath',
-            action='store_true',
-            help='List the absolute path of wheels')
+            '--format',
+            action='store',
+            dest='list_format',
+            default="human",
+            choices=('human', 'abspath'),
+            help="Select the output format among: human (default) or abspath"
+        )
 
         self.parser.insert_option_group(0, self.cmd_opts)
 
@@ -126,22 +130,34 @@ class CacheCommand(Command):
             pattern = '*'
 
         files = self._find_wheels(options, pattern)
+        if options.list_format == 'human':
+            self.format_for_human(files)
+        else:
+            self.format_for_abspath(files)
 
+    def format_for_human(self, files):
+        # type: (List[str]) -> None
         if not files:
-            if not options.abspath:
-                logger.info('Nothing cached.')
+            logger.info('Nothing cached.')
             return
 
         results = []
         for filename in files:
             wheel = os.path.basename(filename)
             size = filesystem.format_file_size(filename)
-            if options.abspath:
-                results.append(filename)
-            else:
-                results.append(' - {} ({})'.format(wheel, size))
-        if not options.abspath:
-            logger.info('Cache contents:\n')
+            results.append(' - {} ({})'.format(wheel, size))
+        logger.info('Cache contents:\n')
+        logger.info('\n'.join(sorted(results)))
+
+    def format_for_abspath(self, files):
+        # type: (List[str]) -> None
+        if not files:
+            return
+
+        results = []
+        for filename in files:
+            results.append(filename)
+
         logger.info('\n'.join(sorted(results)))
 
     def remove_cache_items(self, options, args):

tests/functional/test_cache.py

@@ -72,7 +72,7 @@ def list_matches_wheel(wheel_name, result):
 
 def list_matches_wheel_abspath(wheel_name, result):
     """Returns True if any line in `result`, which should be the output of
-    a `pip cache list --abspath` call, is a valid path and belongs to
+    a `pip cache list --format=abspath` call, is a valid path and belongs to
     `wheel_name`.
 
     E.g., If wheel_name is `foo-1.2.3` it searches for a line starting with
@@ -147,9 +147,9 @@ def test_cache_list(script):
 
 @pytest.mark.usefixtures("populate_wheel_cache")
 def test_cache_list_abspath(script):
-    """Running `pip cache list --abspath` should return full
+    """Running `pip cache list --format=abspath` should return full
     paths of exactly what the populate_wheel_cache fixture adds."""
-    result = script.pip('cache', 'list', '--abspath')
+    result = script.pip('cache', 'list', '--format=abspath')
 
     assert list_matches_wheel_abspath('yyy-1.2.3', result)
     assert list_matches_wheel_abspath('zzz-4.5.6', result)
@@ -167,9 +167,9 @@ def test_cache_list_with_empty_cache(script):
 
 @pytest.mark.usefixtures("empty_wheel_cache")
 def test_cache_list_with_empty_cache_abspath(script):
-    """Running `pip cache list --abspath` with an empty cache should not
+    """Running `pip cache list --format=abspath` with an empty cache should not
     print anything and exit."""
-    result = script.pip('cache', 'list', '--abspath')
+    result = script.pip('cache', 'list', '--format=abspath')
     assert result.stdout.strip() == ""
 
 
@@ -193,9 +193,10 @@ def test_cache_list_name_match(script):
 
 @pytest.mark.usefixtures("populate_wheel_cache")
 def test_cache_list_name_match_abspath(script):
-    """Running `pip cache list zzz --abspath` should list paths of
+    """Running `pip cache list zzz --format=abspath` should list paths of
     zzz-4.5.6, zzz-4.5.7, zzz-7.8.9, but nothing else."""
-    result = script.pip('cache', 'list', 'zzz', '--abspath', '--verbose')
+    result = script.pip('cache', 'list', 'zzz', '--format=abspath',
+                        '--verbose')
 
     assert not list_matches_wheel_abspath('yyy-1.2.3', result)
     assert list_matches_wheel_abspath('zzz-4.5.6', result)
@@ -217,9 +218,10 @@ def test_cache_list_name_and_version_match(script):
 
 @pytest.mark.usefixtures("populate_wheel_cache")
 def test_cache_list_name_and_version_match_abspath(script):
-    """Running `pip cache list zzz-4.5.6 --abspath` should list path of
+    """Running `pip cache list zzz-4.5.6 --format=abspath` should list path of
     zzz-4.5.6, but nothing else."""
-    result = script.pip('cache', 'list', 'zzz-4.5.6', '--abspath', '--verbose')
+    result = script.pip('cache', 'list', 'zzz-4.5.6', '--format=abspath',
+                        '--verbose')
 
     assert not list_matches_wheel_abspath('yyy-1.2.3', result)
     assert list_matches_wheel_abspath('zzz-4.5.6', result)