label-based slicing . . . . . . . . . . . . . . . . . . . . . . . . . . . 314 1.28.4 Changes to Series [] operator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 315 1.28.5 Other API Changes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 556 13.14.5 Special use of the == operator with list objects . . . . . . . . . . . . . . . . . . . . . . . 557 13.14.6 Boolean Operators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1036 29.1.2 Using the in operator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1036 29.2 NaN, Integer

label-based slicing . . . . . . . . . . . . . . . . . . . . . . . . . . . 313 1.27.4 Changes to Series [] operator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 314 1.27.5 Other API Changes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 554 13.14.5 Special use of the == operator with list objects . . . . . . . . . . . . . . . . . . . . . . . 555 13.14.6 Boolean Operators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1034 29.1.2 Using the in operator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1034 29.2 NaN, Integer

duplicated/drop_duplicates with a Categorical (GH8623) • Bug in Categorical reflected comparison operator raising if the first argument was a numpy array scalar (e.g. np.int64) (GH8658) • Bug in Panel arrays containing NaN for equality (GH7065) • Bug in DataFrame.eval() where the dtype of the not operator (~) was not correctly inferred as bool. 1.4 v0.14.1 (July 11, 2014) This is a minor release from should do x | y instead x / y # this raises because it doesn’t make sense NotImplementedError: operator ’/’ not implemented for bool dtypes • In HDFStore, select_as_multiple will always raise a KeyError

duplicated/drop_duplicates with a Categorical (GH8623) • Bug in Categorical reflected comparison operator raising if the first argument was a numpy array scalar (e.g. np.int64) (GH8658) • Bug in Panel arrays containing NaN for equality (GH7065) • Bug in DataFrame.eval() where the dtype of the not operator (~) was not correctly inferred as bool. 1.2. v0.15.0 (October 18, 2014) 35 pandas: powerful Python should do x | y instead x / y # this raises because it doesn’t make sense NotImplementedError: operator ’/’ not implemented for bool dtypes • In HDFStore, select_as_multiple will always raise a KeyError

DateOffset(years=1) Out[68]: Timestamp('2016-10-09 20:59:45.919984') Changes to Index Comparisons Operator equal on Index should behavior similarly to Series (GH9947, GH10637) Starting in v0.17.0, comparing side is a DataFrame (GH11014) • Bug that returns None and does not raise NotImplementedError when operator functions (e.g. .add) of Panel are not implemented (GH7692) • Bug in line and kde plot cannot accept text through processes. More recently dplyr and magrittr have introduced the popular (%>%) pipe operator for R. See the documentation for more. (GH10129) Other Enhancements • Added rsplit to Index/Series

incompatible API changes 15 pandas: powerful Python data analysis toolkit, Release 0.25.0 The in operator (__contains__) now only returns True for exact matches to Intervals in the IntervalIndex, whereas MultiIndex (GH26944) • Bug in Categorical and CategoricalIndex with Interval values when using the in operator (__contains) with objects that are not comparable to the values in the Interval (GH23705) • Bug Categorical incorrectly raising ValueError instead of TypeError when a list is passed using the in operator (__contains__) (GH21729) • Bug in setting a new value in a Series with a Timedelta object incorrectly

incompatible API changes 15 pandas: powerful Python data analysis toolkit, Release 0.25.1 The in operator (__contains__) now only returns True for exact matches to Intervals in the IntervalIndex, whereas MultiIndex (GH26944) • Bug in Categorical and CategoricalIndex with Interval values when using the in operator (__contains) with objects that are not comparable to the values in the Interval (GH23705) • Bug Categorical incorrectly raising ValueError instead of TypeError when a list is passed using the in operator (__contains__) (GH21729) • Bug in setting a new value in a Series with a Timedelta object incorrectly

respectively) (GH22938) Operator support A Series based on an ExtensionArray now supports arithmetic and comparison operators (GH19577). There are two approaches for providing operator support for an ExtensionArray: 2. Use an operator implementation from pandas that depends on operators that are already defined on the underly- ing elements (scalars) of the ExtensionArray. See the ExtensionArray Operator Support documentation documentation section for details on both ways of adding operator support. Other changes • A default repr for pandas.api.extensions.ExtensionArray is now provided (GH23601). • ExtensionArray._formatting_values()

label-based slicing . . . . . . . . . . . . . . . . . . . . . . . . . . . 362 1.32.4 Changes to Series [] operator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 363 1.32.5 Other API Changes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 617 12.15.5 Special use of the == operator with list objects . . . . . . . . . . . . . . . . . . . . . . . 619 12.15.6 Boolean Operators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1136 28.2.2 Using the in operator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1136 28.3 NaN, Integer

label-based slicing . . . . . . . . . . . . . . . . . . . . . . . . . . . 360 1.31.4 Changes to Series [] operator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 361 1.31.5 Other API Changes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 615 12.15.5 Special use of the == operator with list objects . . . . . . . . . . . . . . . . . . . . . . . 617 12.15.6 Boolean Operators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1134 28.2.2 Using the in operator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1134 28.3 NaN, Integer