clean up imports ; remove deprecated pandas.tools.merge.concat import

Author: jreback

pandas_gbq/gbq.py

@@ -9,9 +9,7 @@
 import numpy as np
 
 from distutils.version import StrictVersion
-from pandas import compat
-from pandas.core.api import DataFrame
-from pandas.tools.merge import concat
+from pandas import compat, DataFrame, concat
 from pandas.core.common import PandasError
 from pandas.compat import lzip, bytes_to_str
 

pandas_gbq/tests/test_gbq.py

@@ -13,9 +13,8 @@
 from distutils.version import StrictVersion
 from pandas import compat
 
-from pandas import NaT
 from pandas.compat import u, range
-from pandas.core.frame import DataFrame
+from pandas import NaT, DataFrame
 from pandas_gbq import gbq
 import pandas.util.testing as tm
 from pandas.compat.numpy import np_datetime64_compat