value_labels . . . . . . . . . . . . . . . . . . . . . . . 1258 34.1.13.5 pandas.io.stata.StataReader.variable_labels . . . . . . . . . . . . . . . . . . . . . . 1258 34.1.13.6 pandas.io.stata.StataWriter.write_file The .groupby(..).agg(..), .rolling(..).agg(..), and .resample(..).agg(..) syntax can ac- cept a variable of inputs, including scalars, list, and a dict of column names to scalars or lists. This provides 09:00:03 3.0 2013-01-01 09:00:05 NaN 2013-01-01 09:00:06 NaN Using the time-specification generates variable windows for this sparse data. In [20]: dft.rolling('2s').sum() Out[20]: B foo 2013-01-01 09:00:00

DataFrame column attribute access and IPython completion If a DataFrame column label is a valid Python variable name, the column can be accessed like attributes: 5.2. DataFrame 39 pandas: powerful Python data either a panel model or a regular linear model. If the y variable is a DataFrame, the result will be a panel model. In this case, the x variable must either be a Panel, or a dict of DataFrame (which will model 1, resid 247 -----------------------Summary of Estimated Coefficients------------------------ Variable Coef Std Err t-stat p-value CI 2.5% CI 97.5% -------------------------------------------------

DataFrame column attribute access and IPython completion If a DataFrame column label is a valid Python variable name, the column can be accessed like attributes: 5.2. DataFrame 39 pandas: powerful Python data either a panel model or a regular linear model. If the y variable is a DataFrame, the result will be a panel model. In this case, the x variable must either be a Panel, or a dict of DataFrame (which will model 1, resid 247 -----------------------Summary of Estimated Coefficients------------------------ Variable Coef Std Err t-stat p-value CI 2.5% CI 97.5% -------------------------------------------------

value_labels . . . . . . . . . . . . . . . . . . . . . . . 1219 34.1.12.5 pandas.io.stata.StataReader.variable_labels . . . . . . . . . . . . . . . . . . . . . . 1219 34.1.12.6 pandas.io.stata.StataWriter.write_file The .groupby(..).agg(..), .rolling(..).agg(..), and .resample(..).agg(..) syntax can ac- cept a variable of inputs, including scalars, list, and a dict of column names to scalars or lists. This provides 09:00:03 3.0 2013-01-01 09:00:05 NaN 2013-01-01 09:00:06 NaN Using the time-specification generates variable windows for this sparse data. In [20]: dft.rolling('2s').sum() Out[20]: B foo 2013-01-01 09:00:00

value_labels . . . . . . . . . . . . . . . . . . . . . . . 1217 34.1.12.5 pandas.io.stata.StataReader.variable_labels . . . . . . . . . . . . . . . . . . . . . . 1217 34.1.12.6 pandas.io.stata.StataWriter.write_file The .groupby(..).agg(..), .rolling(..).agg(..), and .resample(..).agg(..) syntax can ac- cept a variable of inputs, including scalars, list, and a dict of column names to scalars or lists. This provides 09:00:03 3.0 2013-01-01 09:00:05 NaN 2013-01-01 09:00:06 NaN Using the time-specification generates variable windows for this sparse data. In [20]: dft.rolling('2s').sum() Out[20]: B foo 2013-01-01 09:00:00

Regression Results ============================================================================== Dep. Variable: hr R-squared: 0.685 Model: OLS Adj. R-squared: 0.665 Method: Least Squares F-statistic: 34.28 DataFrame column attribute access and IPython completion If a DataFrame column label is a valid Python variable name, the column can be accessed like an attribute: In [131]: df = pd.DataFrame({'foo1': np.random 'weight': [130, 150]}) ....: In [33]: pd.melt(cheese, id_vars=['first', 'last']) Out[33]: first last variable value 0 John Doe height 5.5 1 Mary Bo height 6.0 2 John Doe weight 130.0 3 Mary Bo weight 150.0

7 4 NaN 5 11 6 13 dtype: float64 • Added a DataFrame.round method to round the values to a variable number of decimal places (GH10568). In [49]: df = pd.DataFrame(np.random.random([3, 3]), columns=['A' Regression Results ============================================================================== Dep. Variable: hr No. Observations: 68 Model: Poisson Df Residuals: 63 Method: MLE Df Model: 4 Date: Fri, 09 an existing grid of axes (GH9158) • Bug in transform and filter when grouping on a categorical variable (GH9921) • Bug in transform when groups are equal in number and dtype to the input index (GH9700)

subplots=True may draw unnecessary minor xticks and yticks (GH7801) • Bug in StataReader which did not read variable labels in 117 files due to difference between Stata docu- mentation and implementation (GH7816) month/quarter/year defined by the frequency of the DateTimeIndex / Timestamp (GH4565, GH6998) • Local variable usage has changed in pandas.eval()/DataFrame.eval()/DataFrame.query() (GH5987). For the DataFrame locals – Local variables must be referred to explicitly. This means that even if you have a local variable that is not a column you must still refer to it with the ’@’ prefix. – You can have an expression

month/quarter/year defined by the frequency of the DateTimeIndex / Timestamp (GH4565, GH6998) • Local variable usage has changed in pandas.eval()/DataFrame.eval()/DataFrame.query() (GH5987). For the DataFrame locals – Local variables must be referred to explicitly. This means that even if you have a local variable that is not a column you must still refer to it with the ’@’ prefix. – You can have an expression all of the open handles are 0. Essentially you have a local instance of HDFStore referenced by a variable. Once you close it, it will report closed. Other references (to the same file) will continue to

value_labels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1118 pandas.io.stata.StataReader.variable_labels . . . . . . . . . . . . . . . . . . . . . . . . . . . 1118 pandas.io.stata.StataWriter.write_file 09:00:03 3.0 2013-01-01 09:00:05 NaN 2013-01-01 09:00:06 NaN Using the time-specification generates variable windows for this sparse data. In [20]: dft.rolling('2s').sum() Out[20]: B foo 2013-01-01 09:00:00 append now supports the ignore_index option (GH13677) • .to_stata() and StataWriter can now write variable labels to Stata dta files using a dictionary to make column names to labels (GH13535, GH13536)