PERF: add copy=True argument to pd.concat to enable pass-thru concats with complete blocks (GH8252)
Merge pull request #8331 from jreback/concat_copy

PERF: add copy=True argument to pd.concat to enable pass-thru concats with complete blocks (GH8252)
CLN: pep8 clean up of sql.py
TST:  test_precision_conversion on windows fix (GH8324)
Merge pull request #8340 from jorisvandenbossche/sql-pep8

CLN: pep8 clean up of sql.py