Apply pylint to scripts/hiddenapi/generate_hiddenapi_lists*

1. Run pyformat scripts/hiddenapi/generate_hiddenapi_lists.py -s 4
--force_quote_type none -i to fix formatting. Some double quotes change
to single quotes since pyformat enforces consistent quotes
2. change map/filter to list comprehension to fix pylint's bad-builtin
warning
3. use pylint: disable=<X> where fixes are not obvious

Test: m generate_hiddenapi_lists_test
Test: pylint --rcfile tools/repohooks/tools/pylintrc <file1>
<file1_test>
Bug: 195738175

Change-Id: I15e71d8d81f0e3fa66d84e6e62eb1848963136e6
diff --git a/scripts/hiddenapi/generate_hiddenapi_lists.py b/scripts/hiddenapi/generate_hiddenapi_lists.py
index 5ab93d1..35e0948 100755
--- a/scripts/hiddenapi/generate_hiddenapi_lists.py
+++ b/scripts/hiddenapi/generate_hiddenapi_lists.py
@@ -16,8 +16,6 @@
 """Generate API lists for non-SDK API enforcement."""
 import argparse
 from collections import defaultdict, namedtuple
-import functools
-import os
 import re
 import sys
 
@@ -60,15 +58,15 @@
 # For example, the max-target-P list is checked in as it was in P,
 # but signatures have changes since then. The flag instructs this
 # script to skip any entries which do not exist any more.
-FLAG_IGNORE_CONFLICTS = "ignore-conflicts"
+FLAG_IGNORE_CONFLICTS = 'ignore-conflicts'
 
 # Option specified after one of FLAGS_API_LIST to express that all
 # apis within a given set of packages should be assign the given flag.
-FLAG_PACKAGES = "packages"
+FLAG_PACKAGES = 'packages'
 
 # Option specified after one of FLAGS_API_LIST to indicate an extra
 # tag that should be added to the matching APIs.
-FLAG_TAG = "tag"
+FLAG_TAG = 'tag'
 
 # Regex patterns of fields/methods used in serialization. These are
 # considered public API despite being hidden.
@@ -84,24 +82,30 @@
 
 # Single regex used to match serialization API. It combines all the
 # SERIALIZATION_PATTERNS into a single regular expression.
-SERIALIZATION_REGEX = re.compile(r'.*->(' + '|'.join(SERIALIZATION_PATTERNS) + r')$')
+SERIALIZATION_REGEX = re.compile(r'.*->(' + '|'.join(SERIALIZATION_PATTERNS) +
+                                 r')$')
 
 # Predicates to be used with filter_apis.
-HAS_NO_API_LIST_ASSIGNED = lambda api, flags: not FLAGS_API_LIST_SET.intersection(flags)
+HAS_NO_API_LIST_ASSIGNED = \
+    lambda api,flags: not FLAGS_API_LIST_SET.intersection(flags)
+
 IS_SERIALIZATION = lambda api, flags: SERIALIZATION_REGEX.match(api)
 
 
 class StoreOrderedOptions(argparse.Action):
-    """An argparse action that stores a number of option arguments in the order that
-    they were specified.
+    """An argparse action that stores a number of option arguments in the order
+
+    that they were specified.
     """
-    def __call__(self, parser, args, values, option_string = None):
+
+    def __call__(self, parser, args, values, option_string=None):
         items = getattr(args, self.dest, None)
         if items is None:
             items = []
         items.append([option_string.lstrip('-'), values])
         setattr(args, self.dest, items)
 
+
 def get_args():
     """Parses command line arguments.
 
@@ -110,22 +114,43 @@
     """
     parser = argparse.ArgumentParser()
     parser.add_argument('--output', required=True)
-    parser.add_argument('--csv', nargs='*', default=[], metavar='CSV_FILE',
+    parser.add_argument(
+        '--csv',
+        nargs='*',
+        default=[],
+        metavar='CSV_FILE',
         help='CSV files to be merged into output')
 
     for flag in ALL_FLAGS:
-        parser.add_argument('--' + flag, dest='ordered_flags', metavar='TXT_FILE',
-            action=StoreOrderedOptions, help='lists of entries with flag "' + flag + '"')
-    parser.add_argument('--' + FLAG_IGNORE_CONFLICTS, dest='ordered_flags', nargs=0,
-        action=StoreOrderedOptions, help='Indicates that only known and otherwise unassigned '
-        'entries should be assign the given flag. Must follow a list of entries and applies '
-        'to the preceding such list.')
-    parser.add_argument('--' + FLAG_PACKAGES, dest='ordered_flags', nargs=0,
-        action=StoreOrderedOptions, help='Indicates that the previous list of entries '
-        'is a list of packages. All members in those packages will be given the flag. '
-        'Must follow a list of entries and applies to the preceding such list.')
-    parser.add_argument('--' + FLAG_TAG, dest='ordered_flags', nargs=1,
-        action=StoreOrderedOptions, help='Adds an extra tag to the previous list of entries. '
+        parser.add_argument(
+            '--' + flag,
+            dest='ordered_flags',
+            metavar='TXT_FILE',
+            action=StoreOrderedOptions,
+            help='lists of entries with flag "' + flag + '"')
+    parser.add_argument(
+        '--' + FLAG_IGNORE_CONFLICTS,
+        dest='ordered_flags',
+        nargs=0,
+        action=StoreOrderedOptions,
+        help='Indicates that only known and otherwise unassigned '
+        'entries should be assign the given flag. Must follow a list of '
+        'entries and applies to the preceding such list.')
+    parser.add_argument(
+        '--' + FLAG_PACKAGES,
+        dest='ordered_flags',
+        nargs=0,
+        action=StoreOrderedOptions,
+        help='Indicates that the previous list of entries '
+        'is a list of packages. All members in those packages will be given '
+        'the flag. Must follow a list of entries and applies to the preceding '
+        'such list.')
+    parser.add_argument(
+        '--' + FLAG_TAG,
+        dest='ordered_flags',
+        nargs=1,
+        action=StoreOrderedOptions,
+        help='Adds an extra tag to the previous list of entries. '
         'Must follow a list of entries and applies to the preceding such list.')
 
     return parser.parse_args()
@@ -143,9 +168,9 @@
         Lines of the file as a list of string.
     """
     with open(filename, 'r') as f:
-        lines = f.readlines();
-    lines = filter(lambda line: not line.startswith('#'), lines)
-    lines = map(lambda line: line.strip(), lines)
+        lines = f.readlines()
+    lines = [line for line in lines if not line.startswith('#')]
+    lines = [line.strip() for line in lines]
     return set(lines)
 
 
@@ -156,7 +181,7 @@
         filename (string): Path to the file to be writing into.
         lines (list): List of strings to write into the file.
     """
-    lines = map(lambda line: line + '\n', lines)
+    lines = [line + '\n' for line in lines]
     with open(filename, 'w') as f:
         f.writelines(lines)
 
@@ -170,17 +195,19 @@
     Returns:
         The package name of the class containing the field/method.
     """
-    full_class_name = signature.split(";->")[0]
+    full_class_name = signature.split(';->')[0]
     # Example: Landroid/hardware/radio/V1_2/IRadio$Proxy
-    if (full_class_name[0] != "L"):
-        raise ValueError("Expected to start with 'L': %s" % full_class_name)
+    if full_class_name[0] != 'L':
+        raise ValueError("Expected to start with 'L': %s"
+                         % full_class_name)
     full_class_name = full_class_name[1:]
     # If full_class_name doesn't contain '/', then package_name will be ''.
-    package_name = full_class_name.rpartition("/")[0]
+    package_name = full_class_name.rpartition('/')[0]
     return package_name.replace('/', '.')
 
 
 class FlagsDict:
+
     def __init__(self):
         self._dict_keyset = set()
         self._dict = defaultdict(set)
@@ -188,37 +215,43 @@
     def _check_entries_set(self, keys_subset, source):
         assert isinstance(keys_subset, set)
         assert keys_subset.issubset(self._dict_keyset), (
-            "Error: {} specifies signatures not present in code:\n"
-            "{}"
-            "Please visit go/hiddenapi for more information.").format(
-                source, "".join(map(lambda x: "  " + str(x) + "\n", keys_subset - self._dict_keyset)))
+            'Error: {} specifies signatures not present in code:\n'
+            '{}'
+            'Please visit go/hiddenapi for more information.').format(
+                source, ''.join(
+                    ['  ' + str(x) + '\n' for x in
+                     keys_subset - self._dict_keyset]))
 
     def _check_flags_set(self, flags_subset, source):
         assert isinstance(flags_subset, set)
         assert flags_subset.issubset(ALL_FLAGS_SET), (
-            "Error processing: {}\n"
-            "The following flags were not recognized: \n"
-            "{}\n"
-            "Please visit go/hiddenapi for more information.").format(
-                source, "\n".join(flags_subset - ALL_FLAGS_SET))
+            'Error processing: {}\n'
+            'The following flags were not recognized: \n'
+            '{}\n'
+            'Please visit go/hiddenapi for more information.').format(
+                source, '\n'.join(flags_subset - ALL_FLAGS_SET))
 
     def filter_apis(self, filter_fn):
         """Returns APIs which match a given predicate.
 
-        This is a helper function which allows to filter on both signatures (keys) and
-        flags (values). The built-in filter() invokes the lambda only with dict's keys.
+        This is a helper function which allows to filter on both signatures
+        (keys) and
+        flags (values). The built-in filter() invokes the lambda only with
+        dict's keys.
 
         Args:
-            filter_fn : Function which takes two arguments (signature/flags) and returns a boolean.
+            filter_fn : Function which takes two arguments (signature/flags) and
+              returns a boolean.
 
         Returns:
             A set of APIs which match the predicate.
         """
-        return set(filter(lambda x: filter_fn(x, self._dict[x]), self._dict_keyset))
+        return {x for x in self._dict_keyset if filter_fn(x, self._dict[x])}
 
     def get_valid_subset_of_unassigned_apis(self, api_subset):
-        """Sanitizes a key set input to only include keys which exist in the dictionary
-        and have not been assigned any API list flags.
+        """Sanitizes a key set input to only include keys which exist in the
+
+        dictionary and have not been assigned any API list flags.
 
         Args:
             entries_subset (set/list): Key set to be sanitized.
@@ -227,7 +260,8 @@
             Sanitized key set.
         """
         assert isinstance(api_subset, set)
-        return api_subset.intersection(self.filter_apis(HAS_NO_API_LIST_ASSIGNED))
+        return api_subset.intersection(
+            self.filter_apis(HAS_NO_API_LIST_ASSIGNED))
 
     def generate_csv(self):
         """Constructs CSV entries from a dictionary.
@@ -235,15 +269,16 @@
         Old versions of flags are used to generate the file.
 
         Returns:
-            List of lines comprising a CSV file. See "parse_and_merge_csv" for format description.
+            List of lines comprising a CSV file. See "parse_and_merge_csv" for
+            format description.
         """
         lines = []
         for api in self._dict:
-          flags = sorted(self._dict[api])
-          lines.append(",".join([api] + flags))
+            flags = sorted(self._dict[api])
+            lines.append(','.join([api] + flags))
         return sorted(lines)
 
-    def parse_and_merge_csv(self, csv_lines, source = "<unknown>"):
+    def parse_and_merge_csv(self, csv_lines, source='<unknown>'):
         """Parses CSV entries and merges them into a given dictionary.
 
         The expected CSV format is:
@@ -251,21 +286,20 @@
 
         Args:
             csv_lines (list of strings): Lines read from a CSV file.
-            source (string): Origin of `csv_lines`. Will be printed in error messages.
-
-        Throws:
-            AssertionError if parsed flags are invalid.
+            source (string): Origin of `csv_lines`. Will be printed in error
+              messages.
+        Throws: AssertionError if parsed flags are invalid.
         """
         # Split CSV lines into arrays of values.
-        csv_values = [ line.split(',') for line in csv_lines ]
+        csv_values = [line.split(',') for line in csv_lines]
 
         # Update the full set of API signatures.
-        self._dict_keyset.update([ csv[0] for csv in csv_values ])
+        self._dict_keyset.update([csv[0] for csv in csv_values])
 
         # Check that all flags are known.
         csv_flags = set()
         for csv in csv_values:
-          csv_flags.update(csv[1:])
+            csv_flags.update(csv[1:])
         self._check_flags_set(csv_flags, source)
 
         # Iterate over all CSV lines, find entry in dict and append flags to it.
@@ -275,47 +309,53 @@
                 flags.append(FLAG_SDK)
             self._dict[csv[0]].update(flags)
 
-    def assign_flag(self, flag, apis, source="<unknown>", tag = None):
+    def assign_flag(self, flag, apis, source='<unknown>', tag=None):
         """Assigns a flag to given subset of entries.
 
         Args:
             flag (string): One of ALL_FLAGS.
             apis (set): Subset of APIs to receive the flag.
-            source (string): Origin of `entries_subset`. Will be printed in error messages.
-
-        Throws:
-            AssertionError if parsed API signatures of flags are invalid.
+            source (string): Origin of `entries_subset`. Will be printed in
+              error messages.
+        Throws: AssertionError if parsed API signatures of flags are invalid.
         """
         # Check that all APIs exist in the dict.
         self._check_entries_set(apis, source)
 
         # Check that the flag is known.
-        self._check_flags_set(set([ flag ]), source)
+        self._check_flags_set(set([flag]), source)
 
-        # Iterate over the API subset, find each entry in dict and assign the flag to it.
+        # Iterate over the API subset, find each entry in dict and assign the
+        # flag to it.
         for api in apis:
             self._dict[api].add(flag)
             if tag:
                 self._dict[api].add(tag)
 
 
-FlagFile = namedtuple('FlagFile', ('flag', 'file', 'ignore_conflicts', 'packages', 'tag'))
+FlagFile = namedtuple('FlagFile',
+                      ('flag', 'file', 'ignore_conflicts', 'packages', 'tag'))
+
 
 def parse_ordered_flags(ordered_flags):
     r = []
-    currentflag, file, ignore_conflicts, packages, tag = None, None, False, False, None
+    currentflag, file, ignore_conflicts, packages, tag = None, None, False, \
+        False, None
     for flag_value in ordered_flags:
         flag, value = flag_value[0], flag_value[1]
         if flag in ALL_FLAGS_SET:
             if currentflag:
-                r.append(FlagFile(currentflag, file, ignore_conflicts, packages, tag))
+                r.append(
+                    FlagFile(currentflag, file, ignore_conflicts, packages,
+                             tag))
                 ignore_conflicts, packages, tag = False, False, None
             currentflag = flag
             file = value
         else:
             if currentflag is None:
-                raise argparse.ArgumentError('--%s is only allowed after one of %s' % (
-                    flag, ' '.join(['--%s' % f for f in ALL_FLAGS_SET])))
+                raise argparse.ArgumentError( #pylint: disable=no-value-for-parameter
+                    '--%s is only allowed after one of %s' %
+                    (flag, ' '.join(['--%s' % f for f in ALL_FLAGS_SET])))
             if flag == FLAG_IGNORE_CONFLICTS:
                 ignore_conflicts = True
             elif flag == FLAG_PACKAGES:
@@ -323,13 +363,12 @@
             elif flag == FLAG_TAG:
                 tag = value[0]
 
-
     if currentflag:
         r.append(FlagFile(currentflag, file, ignore_conflicts, packages, tag))
     return r
 
 
-def main(argv):
+def main(argv): #pylint: disable=unused-argument
     # Parse arguments.
     args = vars(get_args())
     flagfiles = parse_ordered_flags(args['ordered_flags'] or [])
@@ -342,7 +381,7 @@
     # contain the full set of APIs. Subsequent additions from text files
     # will be able to detect invalid entries, and/or filter all as-yet
     # unassigned entries.
-    for filename in args["csv"]:
+    for filename in args['csv']:
         flags.parse_and_merge_csv(read_lines(filename), filename)
 
     # Combine inputs which do not require any particular order.
@@ -352,24 +391,28 @@
     # (2) Merge text files with a known flag into the dictionary.
     for info in flagfiles:
         if (not info.ignore_conflicts) and (not info.packages):
-            flags.assign_flag(info.flag, read_lines(info.file), info.file, info.tag)
+            flags.assign_flag(info.flag, read_lines(info.file), info.file,
+                              info.tag)
 
     # Merge text files where conflicts should be ignored.
     # This will only assign the given flag if:
     # (a) the entry exists, and
     # (b) it has not been assigned any other flag.
-    # Because of (b), this must run after all strict assignments have been performed.
+    # Because of (b), this must run after all strict assignments have been
+    # performed.
     for info in flagfiles:
         if info.ignore_conflicts:
-            valid_entries = flags.get_valid_subset_of_unassigned_apis(read_lines(info.file))
-            flags.assign_flag(info.flag, valid_entries, filename, info.tag)
+            valid_entries = flags.get_valid_subset_of_unassigned_apis(
+                read_lines(info.file))
+            flags.assign_flag(info.flag, valid_entries, filename, info.tag) #pylint: disable=undefined-loop-variable
 
-    # All members in the specified packages will be assigned the appropriate flag.
+    # All members in the specified packages will be assigned the appropriate
+    # flag.
     for info in flagfiles:
         if info.packages:
             packages_needing_list = set(read_lines(info.file))
-            should_add_signature_to_list = lambda sig,lists: extract_package(
-                sig) in packages_needing_list and not lists
+            should_add_signature_to_list = lambda sig, lists: extract_package(
+                sig) in packages_needing_list and not lists #pylint: disable=cell-var-from-loop
             valid_entries = flags.filter_apis(should_add_signature_to_list)
             flags.assign_flag(info.flag, valid_entries, info.file, info.tag)
 
@@ -377,7 +420,8 @@
     flags.assign_flag(FLAG_BLOCKED, flags.filter_apis(HAS_NO_API_LIST_ASSIGNED))
 
     # Write output.
-    write_lines(args["output"], flags.generate_csv())
+    write_lines(args['output'], flags.generate_csv())
 
-if __name__ == "__main__":
+
+if __name__ == '__main__':
     main(sys.argv)
diff --git a/scripts/hiddenapi/generate_hiddenapi_lists_test.py b/scripts/hiddenapi/generate_hiddenapi_lists_test.py
index b81424b..204de97 100755
--- a/scripts/hiddenapi/generate_hiddenapi_lists_test.py
+++ b/scripts/hiddenapi/generate_hiddenapi_lists_test.py
@@ -15,34 +15,39 @@
 # limitations under the License.
 """Unit tests for Hidden API list generation."""
 import unittest
-from generate_hiddenapi_lists import *
+from generate_hiddenapi_lists import *  # pylint: disable=wildcard-import,unused-wildcard-import
+
 
 class TestHiddenapiListGeneration(unittest.TestCase):
-
     def test_filter_apis(self):
         # Initialize flags so that A and B are put on the allow list and
         # C, D, E are left unassigned. Try filtering for the unassigned ones.
         flags = FlagsDict()
-        flags.parse_and_merge_csv(['A,' + FLAG_SDK, 'B,' + FLAG_SDK,
-                        'C', 'D', 'E'])
+        flags.parse_and_merge_csv(
+            ['A,' + FLAG_SDK, 'B,' + FLAG_SDK, 'C', 'D', 'E']
+        )
         filter_set = flags.filter_apis(lambda api, flags: not flags)
         self.assertTrue(isinstance(filter_set, set))
-        self.assertEqual(filter_set, set([ 'C', 'D', 'E' ]))
+        self.assertEqual(filter_set, set(['C', 'D', 'E']))
 
     def test_get_valid_subset_of_unassigned_keys(self):
         # Create flags where only A is unassigned.
         flags = FlagsDict()
         flags.parse_and_merge_csv(['A,' + FLAG_SDK, 'B', 'C'])
         flags.assign_flag(FLAG_UNSUPPORTED, set(['C']))
-        self.assertEqual(flags.generate_csv(),
-            [ 'A,' + FLAG_SDK, 'B', 'C,' + FLAG_UNSUPPORTED ])
+        self.assertEqual(
+            flags.generate_csv(),
+            ['A,' + FLAG_SDK, 'B', 'C,' + FLAG_UNSUPPORTED],
+        )
 
         # Check three things:
         # (1) B is selected as valid unassigned
         # (2) A is not selected because it is assigned to the allow list
         # (3) D is not selected because it is not a valid key
         self.assertEqual(
-            flags.get_valid_subset_of_unassigned_apis(set(['A', 'B', 'D'])), set([ 'B' ]))
+            flags.get_valid_subset_of_unassigned_apis(set(['A', 'B', 'D'])),
+            set(['B']),
+        )
 
     def test_parse_and_merge_csv(self):
         flags = FlagsDict()
@@ -51,41 +56,48 @@
         self.assertEqual(flags.generate_csv(), [])
 
         # Test new additions.
-        flags.parse_and_merge_csv([
-            'A,' + FLAG_UNSUPPORTED,
-            'B,' + FLAG_BLOCKED + ',' + FLAG_MAX_TARGET_O,
-            'C,' + FLAG_SDK + ',' + FLAG_SYSTEM_API,
-            'D,' + FLAG_UNSUPPORTED + ',' + FLAG_TEST_API,
-            'E,' + FLAG_BLOCKED + ',' + FLAG_TEST_API,
-        ])
-        self.assertEqual(flags.generate_csv(), [
-            'A,' + FLAG_UNSUPPORTED,
-            'B,' + FLAG_BLOCKED + "," + FLAG_MAX_TARGET_O,
-            'C,' + FLAG_SDK + ',' + FLAG_SYSTEM_API,
-            'D,' + FLAG_TEST_API + ',' + FLAG_UNSUPPORTED,
-            'E,' + FLAG_BLOCKED + ',' + FLAG_TEST_API,
-        ])
+        flags.parse_and_merge_csv(
+            [
+                'A,' + FLAG_UNSUPPORTED,
+                'B,' + FLAG_BLOCKED + ',' + FLAG_MAX_TARGET_O,
+                'C,' + FLAG_SDK + ',' + FLAG_SYSTEM_API,
+                'D,' + FLAG_UNSUPPORTED + ',' + FLAG_TEST_API,
+                'E,' + FLAG_BLOCKED + ',' + FLAG_TEST_API,
+            ]
+        )
+        self.assertEqual(
+            flags.generate_csv(),
+            [
+                'A,' + FLAG_UNSUPPORTED,
+                'B,' + FLAG_BLOCKED + "," + FLAG_MAX_TARGET_O,
+                'C,' + FLAG_SDK + ',' + FLAG_SYSTEM_API,
+                'D,' + FLAG_TEST_API + ',' + FLAG_UNSUPPORTED,
+                'E,' + FLAG_BLOCKED + ',' + FLAG_TEST_API,
+            ],
+        )
 
         # Test unknown flag.
         with self.assertRaises(AssertionError):
-            flags.parse_and_merge_csv([ 'Z,foo' ])
+            flags.parse_and_merge_csv(['Z,foo'])
 
     def test_assign_flag(self):
         flags = FlagsDict()
         flags.parse_and_merge_csv(['A,' + FLAG_SDK, 'B'])
 
         # Test new additions.
-        flags.assign_flag(FLAG_UNSUPPORTED, set([ 'A', 'B' ]))
-        self.assertEqual(flags.generate_csv(),
-            [ 'A,' + FLAG_SDK + "," + FLAG_UNSUPPORTED, 'B,' + FLAG_UNSUPPORTED ])
+        flags.assign_flag(FLAG_UNSUPPORTED, set(['A', 'B']))
+        self.assertEqual(
+            flags.generate_csv(),
+            ['A,' + FLAG_SDK + "," + FLAG_UNSUPPORTED, 'B,' + FLAG_UNSUPPORTED],
+        )
 
         # Test invalid API signature.
         with self.assertRaises(AssertionError):
-            flags.assign_flag(FLAG_SDK, set([ 'C' ]))
+            flags.assign_flag(FLAG_SDK, set(['C']))
 
         # Test invalid flag.
         with self.assertRaises(AssertionError):
-            flags.assign_flag('foo', set([ 'A' ]))
+            flags.assign_flag('foo', set(['A']))
 
     def test_extract_package(self):
         signature = 'Lcom/foo/bar/Baz;->method1()Lcom/bar/Baz;'
@@ -100,5 +112,6 @@
         expected_package = 'com.foo_bar.baz'
         self.assertEqual(extract_package(signature), expected_package)
 
+
 if __name__ == '__main__':
     unittest.main(verbosity=2)