diff --git a/scripts/hiddenapi/signature_patterns.py b/scripts/hiddenapi/signature_patterns.py
index a7c5bb4..0acb2a0 100755
--- a/scripts/hiddenapi/signature_patterns.py
+++ b/scripts/hiddenapi/signature_patterns.py
@@ -13,22 +13,26 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
-"""
-Generate a set of signature patterns from the modular flags generated by a
+"""Generate a set of signature patterns from the modular flags generated by a
 bootclasspath_fragment that can be used to select a subset of monolithic flags
 against which the modular flags can be compared.
 """
 
 import argparse
 import csv
+import sys
 
-def dict_reader(input):
-    return csv.DictReader(input, delimiter=',', quotechar='|', fieldnames=['signature'])
+def dict_reader(csvfile):
+    return csv.DictReader(
+        csvfile, delimiter=',', quotechar='|', fieldnames=['signature']
+    )
+
 
 def produce_patterns_from_file(file):
     with open(file, 'r') as f:
         return produce_patterns_from_stream(f)
 
+
 def produce_patterns_from_stream(stream):
     # Read in all the signatures into a list and remove member names.
     patterns = set()
@@ -38,18 +42,26 @@
         # Remove the class specific member signature
         pieces = text.split(";->")
         qualifiedClassName = pieces[0]
-            # Remove inner class names as they cannot be separated from the containing outer class.
+        # Remove inner class names as they cannot be separated
+        # from the containing outer class.
         pieces = qualifiedClassName.split("$", maxsplit=1)
         pattern = pieces[0]
         patterns.add(pattern)
 
-    patterns = list(patterns)
+    patterns = list(patterns) #pylint: disable=redefined-variable-type
     patterns.sort()
     return patterns
 
+
 def main(args):
-    args_parser = argparse.ArgumentParser(description='Generate a set of signature patterns that select a subset of monolithic hidden API files.')
-    args_parser.add_argument('--flags', help='The stub flags file which contains an entry for every dex member')
+    args_parser = argparse.ArgumentParser(
+        description='Generate a set of signature patterns '
+        'that select a subset of monolithic hidden API files.'
+    )
+    args_parser.add_argument(
+        '--flags',
+        help='The stub flags file which contains an entry for every dex member',
+    )
     args_parser.add_argument('--output', help='Generated signature prefixes')
     args = args_parser.parse_args(args)
 
@@ -62,5 +74,6 @@
             outputFile.write(pattern)
             outputFile.write("\n")
 
+
 if __name__ == "__main__":
     main(sys.argv[1:])