Groupby.col

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Groupby.col
Obtain the column(s) per groups
danfo.Groupby.col(col_names)    [source]
Parameters
Type
Description
Default
col_names
Array
List of column
​
Returns: Groupby Data structure
Note:    This is similar to pandas df.groupby(["column"])["col_names"]
Examples
Obtain a column
Node
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const dfd = require("danfojs-node")
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​
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let data ={'A': ['foo', 'bar', 'foo', 'bar',
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                'foo', 'bar', 'foo', 'foo'],
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           'B': ['one', 'one', 'two', 'three',
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                'two', 'two', 'one', 'three'],
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           'C': [1,3,2,4,5,2,6,7],
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           'D': [3,2,4,1,5,6,7,8]
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        }
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​
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let df = new dfd.DataFrame(data)
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​
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​
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let grp = df.groupby(["A"])
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grp.col(["C"])
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​
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//for more coumns
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grp.col(["C","D"])
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Apparently the output are not that useful unless you perform some operations like max(), count() and the likes. 
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//it returns the groupby data structure
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GroupBy {
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  key_col: [ 'A' ],
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  col_dict: {
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    foo: [ [Array], [Array], [Array], [Array], [Array] ],
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    bar: [ [Array], [Array], [Array] ]
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  },
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  data: [
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    [ 'foo', 'one', 1, 3 ],
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    [ 'bar', 'one', 3, 2 ],
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    [ 'foo', 'two', 2, 4 ],
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    [ 'bar', 'three', 4, 1 ],
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    [ 'foo', 'two', 5, 5 ],
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    [ 'bar', 'two', 2, 6 ],
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    [ 'foo', 'one', 6, 7 ],
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    [ 'foo', 'three', 7, 8 ]
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  ],
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  column_name: [ 'A', 'B', 'C', 'D' ],
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  data_tensors: {
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    foo: DataFrame {
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      kwargs: [Object],
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      series: false,
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      data: [Array],
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      row_data_tensor: [Tensor],
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      index_arr: [Array],
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      columns: [Array],
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      col_data: [Array],
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      col_data_tensor: [Tensor],
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      col_types: [Array],
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      A: [Getter/Setter],
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      B: [Getter/Setter],
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      C: [Getter/Setter],
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      D: [Getter/Setter]
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    },
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    bar: DataFrame {
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      kwargs: [Object],
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      series: false,
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      data: [Array],
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      row_data_tensor: [Tensor],
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      index_arr: [Array],
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      columns: [Array],
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      col_data: [Array],
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      col_data_tensor: [Tensor],
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      col_types: [Array],
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      A: [Getter/Setter],
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      B: [Getter/Setter],
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      C: [Getter/Setter],
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      D: [Getter/Setter]
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    }
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  },
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  group_col_name: [ 'C' ],
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  group_col: { foo: [ [Series] ], bar: [ [Series] ] }
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}
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​
Groupby.get_groups
Groupby.max
Last modified 1yr ago
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