Cleanup verify_overlaps*.py

Fix issues reported by pylint, Intellij Python checks and also try and
adhere to the Google Python Style Guide.

Bug: 194063708
Test: atest --host verify_overlaps_test
      m out/soong/hiddenapi/hiddenapi-flags.csv
      /usr/bin/pylint --rcfile $ANDROID_BUILD_TOP/tools/repohooks/tools/pylintrc scripts/hiddenapi/verify_overlaps*.py
      pyformat -s 4 --force_quote_type single -i scripts/hiddenapi/verify_overlaps*.py
Change-Id: I6273456abc3a4da4af780ae1a0473ca63521dff5
diff --git a/scripts/hiddenapi/verify_overlaps.py b/scripts/hiddenapi/verify_overlaps.py
index e5214df..0d4f669 100755
--- a/scripts/hiddenapi/verify_overlaps.py
+++ b/scripts/hiddenapi/verify_overlaps.py
@@ -23,13 +23,13 @@
 from signature_trie import signature_trie
 
 
-def dict_reader(csvfile):
+def dict_reader(csv_file):
     return csv.DictReader(
-        csvfile, delimiter=",", quotechar="|", fieldnames=["signature"])
+        csv_file, delimiter=",", quotechar="|", fieldnames=["signature"])
 
 
 def read_flag_trie_from_file(file):
-    with open(file, "r") as stream:
+    with open(file, "r", encoding="utf8") as stream:
         return read_flag_trie_from_stream(stream)
 
 
@@ -43,24 +43,24 @@
 
 
 def extract_subset_from_monolithic_flags_as_dict_from_file(
-        monolithicTrie, patternsFile):
+        monolithic_trie, patterns_file):
     """Extract a subset of flags from the dict of monolithic flags.
 
-    :param monolithicFlagsDict: the dict containing all the monolithic flags.
-    :param patternsFile: a file containing a list of signature patterns that
+    :param monolithic_trie: the trie containing all the monolithic flags.
+    :param patterns_file: a file containing a list of signature patterns that
     define the subset.
     :return: the dict from signature to row.
     """
-    with open(patternsFile, "r") as stream:
+    with open(patterns_file, "r", encoding="utf8") as stream:
         return extract_subset_from_monolithic_flags_as_dict_from_stream(
-            monolithicTrie, stream)
+            monolithic_trie, stream)
 
 
 def extract_subset_from_monolithic_flags_as_dict_from_stream(
-        monolithicTrie, stream):
+        monolithic_trie, stream):
     """Extract a subset of flags from the trie of monolithic flags.
 
-    :param monolithicTrie: the trie containing all the monolithic flags.
+    :param monolithic_trie: the trie containing all the monolithic flags.
     :param stream: a stream containing a list of signature patterns that define
     the subset.
     :return: the dict from signature to row.
@@ -68,7 +68,7 @@
     dict_signature_to_row = {}
     for pattern in stream:
         pattern = pattern.rstrip()
-        rows = monolithicTrie.get_matching_rows(pattern)
+        rows = monolithic_trie.get_matching_rows(pattern)
         for row in rows:
             signature = row["signature"]
             dict_signature_to_row[signature] = row
@@ -93,48 +93,48 @@
     return dict_signature_to_row
 
 
-def read_signature_csv_from_file_as_dict(csvFile):
+def read_signature_csv_from_file_as_dict(csv_file):
     """Read the csvFile into a dict.
 
     The first column is assumed to be the signature and used as the
     key.
 
     The whole row is stored as the value.
-    :param csvFile: the csv file to read
+    :param csv_file: the csv file to read
     :return: the dict from signature to row.
     """
-    with open(csvFile, "r") as f:
+    with open(csv_file, "r", encoding="utf8") as f:
         return read_signature_csv_from_stream_as_dict(f)
 
 
-def compare_signature_flags(monolithicFlagsDict, modularFlagsDict):
+def compare_signature_flags(monolithic_flags_dict, modular_flags_dict):
     """Compare the signature flags between the two dicts.
 
-    :param monolithicFlagsDict: the dict containing the subset of the monolithic
-    flags that should be equal to the modular flags.
-    :param modularFlagsDict:the dict containing the flags produced by a single
+    :param monolithic_flags_dict: the dict containing the subset of the
+    monolithic flags that should be equal to the modular flags.
+    :param modular_flags_dict:the dict containing the flags produced by a single
     bootclasspath_fragment module.
     :return: list of mismatches., each mismatch is a tuple where the first item
     is the signature, and the second and third items are lists of the flags from
     modular dict, and monolithic dict respectively.
     """
-    mismatchingSignatures = []
+    mismatching_signatures = []
     # Create a sorted set of all the signatures from both the monolithic and
     # modular dicts.
-    allSignatures = sorted(
-        set(chain(monolithicFlagsDict.keys(), modularFlagsDict.keys())))
-    for signature in allSignatures:
-        monolithicRow = monolithicFlagsDict.get(signature, {})
-        monolithicFlags = monolithicRow.get(None, [])
-        if signature in modularFlagsDict:
-            modularRow = modularFlagsDict.get(signature, {})
-            modularFlags = modularRow.get(None, [])
+    all_signatures = sorted(
+        set(chain(monolithic_flags_dict.keys(), modular_flags_dict.keys())))
+    for signature in all_signatures:
+        monolithic_row = monolithic_flags_dict.get(signature, {})
+        monolithic_flags = monolithic_row.get(None, [])
+        if signature in modular_flags_dict:
+            modular_row = modular_flags_dict.get(signature, {})
+            modular_flags = modular_row.get(None, [])
         else:
-            modularFlags = ["blocked"]
-        if monolithicFlags != modularFlags:
-            mismatchingSignatures.append(
-                (signature, modularFlags, monolithicFlags))
-    return mismatchingSignatures
+            modular_flags = ["blocked"]
+        if monolithic_flags != modular_flags:
+            mismatching_signatures.append(
+                (signature, modular_flags, monolithic_flags))
+    return mismatching_signatures
 
 
 def main(argv):
@@ -149,30 +149,30 @@
     args = args_parser.parse_args(argv[1:])
 
     # Read in all the flags into the trie
-    monolithicFlagsPath = args.monolithicFlags
-    monolithicTrie = read_flag_trie_from_file(monolithicFlagsPath)
+    monolithic_flags_path = args.monolithicFlags
+    monolithic_trie = read_flag_trie_from_file(monolithic_flags_path)
 
     # For each subset specified on the command line, create dicts for the flags
     # provided by the subset and the corresponding flags from the complete set
     # of flags and compare them.
     failed = False
-    for modularPair in args.modularFlags:
-        parts = modularPair.split(":")
-        modularFlagsPath = parts[0]
-        modularPatternsPath = parts[1]
-        modularFlagsDict = read_signature_csv_from_file_as_dict(
-            modularFlagsPath)
-        monolithicFlagsSubsetDict = \
+    for modular_pair in args.modularFlags:
+        parts = modular_pair.split(":")
+        modular_flags_path = parts[0]
+        modular_patterns_path = parts[1]
+        modular_flags_dict = read_signature_csv_from_file_as_dict(
+            modular_flags_path)
+        monolithic_flags_subset_dict = \
             extract_subset_from_monolithic_flags_as_dict_from_file(
-            monolithicTrie, modularPatternsPath)
-        mismatchingSignatures = compare_signature_flags(
-            monolithicFlagsSubsetDict, modularFlagsDict)
-        if mismatchingSignatures:
+                monolithic_trie, modular_patterns_path)
+        mismatching_signatures = compare_signature_flags(
+            monolithic_flags_subset_dict, modular_flags_dict)
+        if mismatching_signatures:
             failed = True
             print("ERROR: Hidden API flags are inconsistent:")
-            print("< " + modularFlagsPath)
-            print("> " + monolithicFlagsPath)
-            for mismatch in mismatchingSignatures:
+            print("< " + modular_flags_path)
+            print("> " + monolithic_flags_path)
+            for mismatch in mismatching_signatures:
                 signature = mismatch[0]
                 print()
                 print("< " + ",".join([signature] + mismatch[1]))