CONTENTS 1 What's New 1.1v0.19.2( December24,2016). 1.1.1 Enhancements 1.1.2 Performance Improvements 1.1.3 Bug Fixes 1.2V0.19.1( November3,2016) 1.2.1 Performance Improvements 1.2.2 Bug Fixes 1.3V0.19.0( October2,2016) 334555688 1.3.1 New features merge_asof for asof-style time-series joining rolling ()Is now time-series aware 10 read csv has improved support for duplicate column names 12 read_csv supports parsing Categorical directly Categorical Concatenation ...14 Semi-Month offsets 15 New Index methods 16 Google BigQuery Enhancements 17 Fine-grained numpy errstate 17 get dummies now returns integer dtypes 17 Downcast values to smallest possible dtype in to_ numeric 17 d development APl pl 18 Other enhancements 19 1.3.2 API ch Series. tolist() will now return Python types Series operators for different indexes .22 Series type promotion on assignment 25 to_datet i me () changes 25 Merging changes 26 describe() changes 27 Period changes 28 Index+/-no longer used for set operations Index. di=ference and symmetric_difference changes ....31 Index. unique consistently returns Index Multi index constructors, groupby and set_index preserve categorical dtypes 32 read csv will progressively enumerate chunks 33 Sparse cha 34 Indexer dtype changes 36 Other API changes ....37 1.3.3 Deprecations 38 1.3.4 Removal of prior version deprecations/changes 1.3.5 Performance Improvements 40 1.3.6 Bug Fixes 1.4V0.18.1(May3,2016) 46 14.1 New features 47 Custom Business hour 47 groupby(.) syntax with window and resample operations 47 Method chaining improvements Partial string indexing on DateTime I ndex when part of a Mu1titrdex Assembling Datetime Other Enhancements 1.4.2 Sparse changes 1, 4.3 API changes upby(.)nth() cha 5 numpy function compatibility 57 Using. apply on groupby resampling 57 Changes in read csv exceptions b 8 to datet ime error changes Other API changes Deprecations 1. 4.4 Performance Improvements 1.4.5 Bug Fixes 1.5V0.18.0( March13,2016) .63 1.5.1 New features b Window functions are now methods 65 Changes to rename R Index Changes to str extract 8 Addition of strextractall Changes to strcat 70 Datetimelike rounding Formatting of Integers in FloatIndex 72 Changes to dtype assignment behaviors to xarra .,,74 Latex Representation .74 pd. read_sas() changes 75 Other enhancements .75 1.5.2 Backwards incompatible API changes Nat and Timedelta operations ..76 Changes to msgpack Signature change for rank 77 Bug in Quarter Begin with n=0 Resample apl 79 Changes to eval Other APi Changes 85 Deprecations 86 Removal of deprecated foat indexers Removal of prior version deprecations/changes 1.5.3 Performance Improvements 1. 5.4 Bug Fixes 1.6V0.17.1( November21,2015) ......93 1.6.1 New features Conditional hTMl, Formatting 1.6.2 Enhancements 94 1.6.3 API changes .96 Deprecations 6 1.6.4 Performance Improvements 96 1.6.5Bug Ixes ..97 1.7V0.17.0 October9,2015) I. 7. New features 00 Datetime with TZ 100 Releasing the gil Plot submethods l02 Additional methods for dt accessor ..,103 Period Frequency Enhancement 104 Support for SAs XPORT files 105 Support for Math Functions in eval .105 Changes to Excel with MultiIndex .105 Google Big Query Enhancements 107 Display Alignment with Unicode East Asian Width 107 Other enhancements b 108 1.7.2 Backwards incompatible API changes 111 Changes to sorting api Changes to to datetime and to timedelta .112 Changes to Index Comparisons .113 Changes to boolean Comparisons vs. None ..114 HDFStore drona behavior 115 Changes to display precision option b 116 Changes to Categorical unique 116 Changes to bool passed as header in Parsers 117 Other api Changes 117 Deprecations 118 Removal of prior version deprecations/changes ...,119 1.7.3 Performance ImpI 120 1. 7. 4 Bug Fixes 120 8V0.16.2(June12,2015) 124 8.1 New features 125 Pil 125 Other enhancements 126 1.8.2 API Changes ....126 1.8.3 Performance Improvements 126 8. 4 Bug Fi 126 1.9V0.16.1(Mayl1,2015) 128 1. 9.1 Enhancements l28 Categoricallndex .129 Sample 131 String methods enhancements 132 Other enhancements .133 1.9.2 API ch 134 Deprecations 134 1.9.3 Index Representation 134 1.9.4 Performance Improvements 136 1.9.5 Bug Fixe 137 1.10V0.16.0( March22,2015) 139 1.10.1 New features 140 DataFrame assign Interaction with scipy sparse 141 String methods enhancements 143 Other enhancements 144 1.10.2 Backwards incompatible aPI changes 145 Changes in Timedelta ..,145 Indexing Changes 146 Categorical changes 147 Other API Changes l49 Deprecations 151 Removal of prior version deprecations/changes 151 1. 10.3 Performance Improvements l51 1. 10.4 Bug Fixes 1.11v0.15.2( December12,2014) 1.11.1 API changes 15 111.2 Enhancements 1.11. 3 Performance 1. 11.4 Bug fixes 1.12V0.15.1( November9,2014)... ..160 1.12.1 API changes b 161 1. 12.2 Enhancements 164 1. 12.3 Bug Fixe 165 1.13v0.15.0( October18,2014) .166 1. 13.1 New features 167 Categoricals in series/Data frame ..167 Timedeltalndex/scalar .169 Men 171 172 Timezone handling improvements 175 Rolling/Expanding Moments improvements 176 Improvements in the sql io module ....179 1.13.2 Backwards incompatible API changes ...,180 Breaking changes ...180 Internal refactoring 185 Deprecations 185 Removal of prior version deprecations/changes I86 1. 13.3 Enhancements 186 1. 13.4 Performance 190 13.5 Bug Fixes ...,190 1.14V0.14.l(July1l,2014) .194 1. 14.1 API changes 194 114.2 Enhancements ..195 1. 14.3 Performance 196 1. 14.4 Experimental 1. 14.5 Bug Fixes 197 1.15w0.14.0(May31,2014) 199 1.15.1API 200 1.15.2 Display Changes 204 1. 15.3 Text Parsing api changes 206 1.15.4 Groupby API Changes 206 15.5SQ 209 1. 15.6 MultiIndexing Using Slicers 210 1.15.7Plot 215 1. 15.8 Prior Version Deprecations/ Changes 216 1.15.9D 115.10 Known issues 218 1. 15.11 Enhancements ...218 1. 15.12 Performance 222 1.15.13 Experimental 222 1. 15.14 Bug fixes 222 16V0.13.l( February3,2014)... 227 1.16.1 Output Formatting enhancements 228 1. 16.2 API changes 230 1.16.3 Prior Version Deprecations/Changes 1. 16.4 Deprecations 231 116.5 Enhancements 231 116.6 Performance 234 1. 16.7 Experimental .,,,,.,,235 1.16.8 Bug Fixe 35 1.17V0.13.0( January3,2014) 1.17.1 API changes .235 1.17.2 Prior Version Deprecations/Changes 238 1.17.3D 238 1. 17.4 Indexing API Changes b 238 1. 17.5 Float64Index api change ....240 1. 17.6 HDFStore API Changes 242 1. I7.7 DataFrame repr Changes 245 1.17.8 Enhancements .245 1. 17.9 Experimental 1.17.10 Internal refactor 17.11 Bug Fi 258 1.18V0.12.0(July24,2013)... 8 118.1 APi Cl 258 118.2 O Enhancements 262 1. 18. 3 Other Enhancements .264 1. 18.4 Experimental Features ..,266 1. 18.5 Bug Fi 266 1.19V0.11.0( April22,2013) 1.19.1 Selection Choices 269 1. 19.2 Selection Deprecations 270 1. 19.3 Dtypes 270 1. 19.4 Dtype Conversion .271 1. 19.5 Dtype Gotchas ..,.272 1. 19.6 Datetimes Conversion 274 1. 19.7 APi changes 276 1. 19.8 Enhancements 276 20V0.1O.( January22,2013). 278 1, 20.1 API changes .278 120.2 New featu 279 120.3 HDEStore 279 1.21v0.10.0( December17,2012) ..284 1. 21.1 File parsing new features 284 1. 21.2 API changes 284 290 1.21.4 Wide DataFrame Printing 290 1. 21.5 Updated PyTables Support 292 1. 21.6 N Dimensional Panels(Experimental) 295 1.22V0.9.1( November14,2012)....... 296 1. 22.1 New features 296 122.2 API changes 299 1.23V0.9.0( October7,2012) ...300 1. 23.1 New features .300 123.2 API changes 301 1.24v0.8.1(July22,2012) 302 1. 24.1 New features 302 1.24.2 Performance improvements 302 1.25v0.8.0(June29,2012) 303 1. 25.1 Support for non-unique indexes 303 1. 25.2 NumPy datetime64 dtype and 1. 6 dependency 1. 25.3 Time series changes and improvements 303 1. 25. 4 Other new features 304 1. 25.5 New plotting methods .,,,,...305 1. 25.6 Other APi changes 306 1.25. 7 Potential porting issues for pandas