. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 639 16.5.5 Replacing Generic Values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 640 16.5.6 String/Regular both the c and python engines, both will now raise an EmptyDataError, a subclass of ValueError, in response to empty columns or header (GH12493, GH12506) Previous behaviour: In [1]: df = pd.read_csv(StringIO('') CParserError is now raised instead of a generic Exception in read_csv when the c engine cannot parse a column (GH12506) • A ValueError is now raised instead of a generic Exception in read_csv when the c engine

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 641 16.5.5 Replacing Generic Values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 642 16.5.6 String/Regular both the c and python engines, both will now raise an EmptyDataError, a subclass of ValueError, in response to empty columns or header (GH12493, GH12506) Previous behaviour: In [1]: df = pd.read_csv(StringIO('') CParserError is now raised instead of a generic Exception in read_csv when the c engine cannot parse a column (GH12506) • A ValueError is now raised instead of a generic Exception in read_csv when the c engine

Limits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 712 15.5.5 Replacing Generic Values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 713 15.5.6 String/Regular both the c and python engines, both will now raise an EmptyDataError, a subclass of ValueError, in response to empty columns or header (GH12493, GH12506) Previous behaviour: In [1]: df = pd.read_csv(StringIO('') CParserError is now raised instead of a generic Exception in read_csv when the c engine cannot parse a column (GH12506) • A ValueError is now raised instead of a generic Exception in read_csv when the c engine

Limits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 709 15.5.5 Replacing Generic Values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 710 15.5.6 String/Regular both the c and python engines, both will now raise an EmptyDataError, a subclass of ValueError, in response to empty columns or header (GH12493, GH12506) Previous behaviour: In [1]: df = pd.read_csv(StringIO('') CParserError is now raised instead of a generic Exception in read_csv when the c engine cannot parse a column (GH12506) • A ValueError is now raised instead of a generic Exception in read_csv when the c engine

Limits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 742 15.5.5 Replacing Generic Values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 743 15.5.6 String/Regular both the c and python engines, both will now raise an EmptyDataError, a subclass of ValueError, in response to empty columns or header (GH12493, GH12506) Previous behaviour: In [1]: df = pd.read_csv(StringIO('') CParserError is now raised instead of a generic Exception in read_csv when the c engine cannot parse a column (GH12506) • A ValueError is now raised instead of a generic Exception in read_csv when the c engine

of hard-coded country codes and the World Bank’s JSON response. In prior versions, the error messages didn’t look at the World Bank’s JSON response. Problem-inducing input were simply dropped prior to the work now, but some bad countries will raise exceptions because some edge cases break the entire response. (GH8482) • Added option to Series.str.split() to return a DataFrame rather than a Series (GH8428) Pickling. • Refactor of series.py/frame.py/panel.py to move common code to generic.py – added _setup_axes to created generic NDFrame structures – moved methods * from_axes,_wrap_array,axes,ix,loc,iloc

of hard-coded country codes and the World Bank’s JSON response. In prior versions, the error messages didn’t look at the World Bank’s JSON response. Problem-inducing input were simply dropped prior to the work now, but some bad countries will raise exceptions because some edge cases break the entire response. (GH8482) • Added option to Series.str.split() to return a DataFrame rather than a Series (GH8428) Pickling. • Refactor of series.py/frame.py/panel.py to move common code to generic.py – added _setup_axes to created generic NDFrame structures – moved methods * from_axes,_wrap_array,axes,ix,loc,iloc

operations when operating with a Series with dtype ‘timedelta64[ns]’ (GH28049) • Bug in core.groupby.generic.SeriesGroupBy.apply() raising ValueError when a column in the original DataFrame is a datetime and Out[432]: bool1 bool2 0 True False 1 False True 2 True False select_dtypes() also works with generic dtypes as well. For example, to select all numeric and boolean columns while excluding unsigned select_dtypes(include=['object']) Out[434]: string 0 a 1 b 2 c To see all the child dtypes of a generic dtype like numpy.number you can define a function that returns a tree of child dtypes: In [435]:

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 581 2.10.10 Replacing generic values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 590 2.10.11 String/regular Out[446]: bool1 bool2 0 True False 1 False True 2 True False select_dtypes() also works with generic dtypes as well. For example, to select all numeric and boolean columns while excluding unsigned select_dtypes(include=["object"]) Out[448]: string 0 a 1 b 2 c To see all the child dtypes of a generic dtype like numpy.number you can define a function that returns a tree of child dtypes: In [449]:

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 607 2.10.10 Replacing generic values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 616 2.10.11 String/regular previous page) bool1 bool2 0 True False 1 False True 2 True False select_dtypes() also works with generic dtypes as well. For example, to select all numeric and boolean columns while excluding unsigned select_dtypes(include=["object"]) Out[448]: string 0 a 1 b 2 c To see all the child dtypes of a generic dtype like numpy.number you can define a function that returns a tree of child dtypes: In [449]: