display dtype info per column (GH5682) • df.info() now honors the option max_info_rows, to disable null counts for large frames (GH5974) In [7]: max_info_rows = pd.get_option(’max_info_rows’) In [8]: date_range(’20130101’,periods=10))) ...: In [9]: df.iloc[3:6,[0,2]] = np.nan # set to not display the null counts In [10]: pd.set_option(’max_info_rows’,0) In [11]: df.info() 4 Chapter 1. What’s New pandas: DataFrame’> Int64Index: 10 entries, 0 to 9 Data columns (total 3 columns): A 7 non-null float64 B 10 non-null float64 C 7 non-null datetime64[ns] dtypes: datetime64[ns](1), float64(2) • Add show_dimensions

display dtype info per column (GH5682) • df.info() now honors the option max_info_rows, to disable null counts for large frames (GH5974) In [7]: max_info_rows = pd.get_option(’max_info_rows’) In [8]: date_range(’20130101’,periods=10))) ...: In [9]: df.iloc[3:6,[0,2]] = np.nan # set to not display the null counts In [10]: pd.set_option(’max_info_rows’,0) In [11]: df.info() DataFrame’> Int64Index: 10 entries, 0 to 9 Data columns (total 3 columns): A 7 non-null float64 B 10 non-null float64 C 7 non-null datetime64[ns] dtypes: datetime64[ns](1), float64(2) • Add show_dimensions

and what is being used now, is np.intp, which corresponds to the C integer size that can hold a pointer (GH3033, GH13972). These types are the same on many platform, but for 64 bit python on Windows, Bug in pd.read_csv() in the C engine where the NULL character was not being parsed as NULL (GH14012) • Bug in pd.read_csv() with engine='c' in which NULL quotechar was not accepted even though quoting rjust, and pad when passing non-integers, did not raise TypeError (GH13598) • Bug in checking for any null objects in a TimedeltaIndex, which always returned True (GH13603) • Bug in Series arithmetic raises

and what is being used now, is np.intp, which corresponds to the C integer size that can hold a pointer (GH3033, GH13972). 34 Chapter 1. What’s New pandas: powerful Python data analysis toolkit, Release being an empty set (GH13402) • Bug in pd.read_csv() in the C engine where the NULL character was not being parsed as NULL (GH14012) 40 Chapter 1. What’s New pandas: powerful Python data analysis toolkit toolkit, Release 0.19.1 • Bug in pd.read_csv() with engine='c' in which NULL quotechar was not accepted even though quoting was specified as None (GH13411) • Bug in pd.read_csv() with engine='c' in which

Out[74]: 0 False 1 False 2 False dtype: bool Usually you simply want to know which values are null. In [75]: s.isnull() Out[75]: 0 False 1 True 2 False dtype: bool Warning: You generally will use isnull/notnull for these types of comparisons, as isnull/notnull tells you which elements are null. One has to be mindful that nan’s don’t compare equal, but None’s do. Note that Pandas/numpy uses length of index (GH11185) • Bug in convert_objects where converted values might not be returned if all null and coerce (GH9589) • Bug in convert_objects where copy keyword was not respected (GH9589) 1.2 v0

tz-aware dtype, similar to pandas.api.types.is_datetime64_any_dtype • DataFrame.asof() will return a null filled Series instead the scalar NaN if a match is not found (GH15118) 34 Chapter 1. What’s New parsed (GH15140) • Bug in pd.read_csv() when an index was specified and no values were specified as null values (GH15835) • Bug in pd.read_csv() in which certain invalid file objects caused the Python interpreter and what is being used now, is np.intp, which corresponds to the C integer size that can hold a pointer (GH3033, GH13972). These types are the same on many platform, but for 64 bit python on Windows,

read_csv() when reading a compressed UTF-16 encoded file (GH18071) • Bug in read_csv() for handling null values in index columns when specifying na_filter=False (GH5239) • Bug in read_csv() when reading Categorical, Index, Series, and DataFrame. (GH15001). The configuration option pd.options.mode.use_inf_as_null is deprecated, and pd.options.mode. use_inf_as_na is added as a replacement. 1.2.2.5 Iteration of issues a UserWarning if the names parameter contains duplicates (GH17095) • read_csv() now treats 'null' and 'n/a' strings as missing values by default (GH16471, GH16078) • pandas.HDFStore‘s string representation

rather than a Series (GH8428) • Added option to df.info(null_counts=None|True|False) to override the default display options and force showing of the null-counts (GH8701) 1.2.3 Bug Fixes • Bug in unpickling indexing with a list-like (GH8710) • Compat issue is DataFrame.dtypes when options.mode.use_inf_as_null is True (GH8722) • Bug in read_csv, dialect parameter would not take a string (:issue: 8703) • Bug Data columns (total 8 columns): bool 5000 non-null bool complex128 5000 non-null complex128 datetime64[ns] 5000 non-null datetime64[ns] float64 5000 non-null float64 1.3. v0.15.0 (October 18, 2014) 19

rather than a Series (GH8428) • Added option to df.info(null_counts=None|True|False) to override the default display options and force showing of the null-counts (GH8701) 1.1.3 Bug Fixes • Bug in unpickling indexing with a list-like (GH8710) • Compat issue is DataFrame.dtypes when options.mode.use_inf_as_null is True (GH8722) • Bug in read_csv, dialect parameter would not take a string (:issue: 8703) • Bug bool 5000 non-null bool complex128 5000 non-null complex128 datetime64[ns] 5000 non-null datetime64[ns] float64 5000 non-null float64 int64 5000 non-null int64 object 5000 non-null object timedelta64[ns]

tz-aware dtype, similar to pandas.api.types.is_datetime64_any_dtype • DataFrame.asof() will return a null filled Series instead the scalar NaN if a match is not found (GH15118) • Specific support for copy Release 0.20.2 • Bug in pd.read_csv() when an index was specified and no values were specified as null values (GH15835) • Bug in pd.read_csv() in which certain invalid file objects caused the Python interpreter and what is being used now, is np.intp, which corresponds to the C integer size that can hold a pointer (GH3033, GH13972). These types are the same on many platform, but for 64 bit python on Windows,