. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 228 9.9 Vectorized string methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 231 9.10 to get indexer and unique values (GH7090) • describe on a DataFrame with a mix of Timestamp and string like objects returns a different Index (GH7088). Previously the index was unintentionally sorted now return a series with dtype=object on empty containers (GH5740) • df.to_csv will now return a string of the CSV data if neither a target path nor a buffer is provided (GH6061) • pd.infer_freq() will

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 202 9.9 Vectorized string methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 204 9.10 fixes a bug that was caused by a combination of having numpy < 1.8, and doing chained assignment on a string-like array. Please review the docs, chained indexing can have unexpected results and should generally See NA Values. • Added Series.str.get_dummies vectorized string method (GH6021), to extract dummy/indicator vari- ables for separated string columns: In [23]: s = Series([’a’, ’a|b’, np.nan, ’a|c’])

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 299 9.9 Vectorized string methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 303 9.10 to use the sqlalchemy String type instead of the default Text type for string columns: from sqlalchemy.types import String data.to_sql(’data_dtype’, engine, dtype={’Col_1’: String}) • Series.all and Series gains an exact keyword to allow for a format to not require an exact match for a provided for- mat string (if its False). exact defaults to True (meaning that exact matching is still the default) (GH8904)

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 291 9.9 Vectorized string methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 295 9.10 options.mode.use_inf_as_null is True (GH8722) • Bug in read_csv, dialect parameter would not take a string (:issue: 8703) • Bug in slicing a multi-index level with an empty-list (GH8737) • Bug in numeric indexing documentation into Indexing and Selecting Data and MultiIndex / Advanced Indexing – Split out string methods documentation into Working with Text Data • Check the API Changes and deprecations before

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 369 10.10 Vectorized string methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 372 10.11 type(df['B'].dtype) Out[7]: pandas.core.dtypes.DatetimeTZDtype Note: There is a slightly different string repr for the underlying DatetimeIndex as a result of the dtype changes, but functionally these are strftime We are now supporting a Series.dt.strftime method for datetime-likes to generate a formatted string (GH10110). Examples: # DatetimeIndex In [13]: s = pd.Series(pd.date_range('20130101', periods=4))

Categorical . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 1.1.5.9 String . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 1.2 v0.21.0 Handling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55 1.5.2.6 Partial String Indexing Changes . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55 1.5.2.7 Concat of different Binary Corr/Cov operations return a MultiIndex DataFrame . . . . . . . . 60 1.5.2.13 HDFStore where string comparison . . . . . . . . . . . . . . . . . . . . . . . . . . 61 1.5.2.14 Index.intersection and

Handling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 1.3.2.6 Partial String Indexing Changes . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 1.3.2.7 Concat of different Binary Corr/Cov operations return a MultiIndex DataFrame . . . . . . . . 31 1.3.2.13 HDFStore where string comparison . . . . . . . . . . . . . . . . . . . . . . . . . . 32 1.3.2.14 Index.intersection and chaininng improvements . . . . . . . . . . . . . . . . . . . . . . . . . . . 95 1.7.1.4 Partial string indexing on DateTimeIndex when part of a MultiIndex . . . . 97 1.7.1.5 Assembling Datetimes . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 154 8.9 Vectorized string methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 156 8.10 DataFrame plotting methods. Accepts either a matplotlib colormap object (ie, matplotlib.cm.jet) or a string name of such an object (ie, ‘jet’). The colormap is sampled to select the color for each column. Currently, PandasObject provides string methods (from StringMixin). (GH4090, GH4092) • New StringMixin that, given a __unicode__ method, gets python 2 and python 3 compatible string methods (__str__, __bytes__

Handling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 1.2.2.6 Partial String Indexing Changes . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 1.2.2.7 Concat of different Binary Corr/Cov operations return a MultiIndex DataFrame . . . . . . . . 29 1.2.2.13 HDFStore where string comparison . . . . . . . . . . . . . . . . . . . . . . . . . . 30 1.2.2.14 Index.intersection and chaininng improvements . . . . . . . . . . . . . . . . . . . . . . . . . . . 93 1.6.1.4 Partial string indexing on DateTimeIndex when part of a MultiIndex . . . . 95 1.6.1.5 Assembling Datetimes . .

chaininng improvements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47 Partial string indexing on DateTimeIndex when part of a MultiIndex . . . . . . . . . . 49 Assembling Datetimes Sample . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129 String Methods Enhancements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 130 Other Interaction with scipy.sparse . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 140 String Methods Enhancements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141 Other