BUG: fix skiprows option for python parser in read_csv
API: raise a TypeError on invalid comparison ops on Series (e.g. integer/datetime) (GH4968)
CLN: do not use mutable default arguments
Fixes issue #4967
Merge pull request #4970 from jreback/invalid_compare

API: raise a TypeError on invalid comparison ops on Series (e.g. integer/datetime) GH4968
Merge pull request #4966 from cpcloud/scatter-matrix-kwargs

CLN: do not use mutable default arguments
Merge pull request #4972 from alefnula/iss4967

CLN: change print to print() in docs
Merge pull request #4969 from guyrt/issue-4382

BUG: fix skiprows option for python parser in read_csv
General print statement cleanup.
Merge pull request #4973 from alefnula/print-cleanup

CLN: General print statement cleanup.