Fixed gpylint warnings for tabulator.py & tabulator_test.py.

I want to use this code to get readability.

BUG=none
TEST=gpylint tabulator.py tabulator_test.py
python tabulator.py
python tabulator_test.py

PRESUBMIT=passed
R=yunlian,bjanakiraman
APPROVED=yunlian
DELTA=128 (93 added, 13 deleted, 22 changed)
OCL=43475677


P4 change: 43505189
2 files changed
tree: bfa020ea24086fe35ae3b045b8a9c1d3483223ca
  1. .git5_specs/
  2. v14/