Series, DataFrame, etc. automatically align the data for you in computations • Powerful, flexible group by functionality to perform split-apply-combine operations on data sets, for both ag- gregating and Grouping By group by we are referring to a process involving one or more of the following steps: • Splitting the data into groups based on some criteria • Applying a function to each group independently Tablewise Function Application: pipe() 2. Row or Column-wise Function Application: apply() 3. Aggregation API: agg() and transform() 4. Applying Elementwise Functions: applymap() Tablewise function application

casting rules and indexing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115 10 Group By: split-apply-combine 117 10.1 Splitting an object into groups . . . . . . . . . . . . . . . . groups . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121 10.3 Aggregation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122 http://stackoverflow.com/questions/tagged/pandas Developer Mailing List: http://groups.google.com/group/pystatsmodels pandas is a Python package providing fast, flexible, and expressive data structures

casting rules and indexing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115 10 Group By: split-apply-combine 117 10.1 Splitting an object into groups . . . . . . . . . . . . . . . . groups . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121 10.3 Aggregation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122 http://stackoverflow.com/questions/tagged/pandas Developer Mailing List: http://groups.google.com/group/pystatsmodels pandas is a Python package providing fast, flexible, and expressive data structures

casting rules and indexing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123 10 Group By: split-apply-combine 125 10.1 Splitting an object into groups . . . . . . . . . . . . . . . . groups . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129 10.3 Aggregation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 130 http://stackoverflow.com/questions/tagged/pandas Developer Mailing List: http://groups.google.com/group/pystatsmodels pandas is a Python package providing fast, flexible, and expressive data structures

functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 766 2.18 Group by: split-apply-combine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 781 2.18.3 Selecting a group . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 782 2.18.4 Aggregation . . . . . . . . . . . . . . . . . . . . . . . convenient data handling functionalities similar to pandas. Learn more Already familiar to SELECT, GROUP BY, JOIN, etc.? Most of these SQL manipulations do have equivalents in pandas. Learn more The data

functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 767 2.18 Group by: split-apply-combine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 782 2.18.3 Selecting a group . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 783 2.18.4 Aggregation . . . . . . . . . . . . . . . . . . . . . . . convenient data handling functionalities similar to pandas. Learn more Already familiar to SELECT, GROUP BY, JOIN, etc.? Most of these SQL manipulations do have equivalents in pandas. Learn more The data

functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 737 2.18 Group by: split-apply-combine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 751 2.18.3 Selecting a group . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 752 2.18.4 Aggregation . . . . . . . . . . . . . . . . . . . . . . . convenient data handling functionalities similar to pandas. Learn more Already familiar to SELECT, GROUP BY, JOIN, etc.? Most of these SQL manipulations do have equivalents in pandas. Learn more The data

functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 772 2.18 Group by: split-apply-combine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 787 2.18.3 Selecting a group . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 788 2.18.4 Aggregation . . . . . . . . . . . . . . . . . . . . . . . convenient data handling functionalities similar to pandas. Learn more Already familiar to SELECT, GROUP BY, JOIN, etc.? Most of these SQL manipulations do have equivalents in pandas. Learn more The data

functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 772 2.18 Group by: split-apply-combine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 787 2.18.3 Selecting a group . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 788 2.18.4 Aggregation . . . . . . . . . . . . . . . . . . . . . . . convenient data handling functionalities similar to pandas. Learn more Already familiar to SELECT, GROUP BY, JOIN, etc.? Most of these SQL manipulations do have equivalents in pandas. Learn more The data

functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 663 2.15.3 Aggregation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 679 2.15 Exponentially weighted windows . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 686 2.16 Group by: split-apply-combine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 699 2.16.3 Selecting a group . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 700 2.16.4 Aggregation . . . . . . . . . . . . . . . . . . . . . . .