Added tags to gitignore, added .style.yapf

.gitignore

@@ -102,3 +102,5 @@ venv.bak/
 
 # mypy
 .mypy_cache/
+/tags
+/tags.*

.style.yapf

@@ -0,0 +1,30 @@
+[style]
+
+# The column limit.
+column_limit=120
+
+# Split before the '.' if we need to split a longer expression:
+#
+#   foo = ('This is a really long string: {}, {}, {}, {}'.format(a, b, c, d))
+#
+# would reformat to something like:
+#
+#   foo = ('This is a really long string: {}, {}, {}, {}'
+#          .format(a, b, c, d))
+split_before_dot=False
+
+# Set to True to split list comprehensions and generators that have
+# non-trivial expressions and multiple clauses before each of these
+# clauses. For example:
+#
+#   result = [
+#       a_long_var + 100 for a_long_var in xrange(1000)
+#       if a_long_var % 10]
+#
+# would reformat to something like:
+#
+#   result = [
+#       a_long_var + 100
+#       for a_long_var in xrange(1000)
+#       if a_long_var % 10]
+split_complex_comprehension=True