DataFrame.apply

danfo.DataFrame.apply(callable, options) [source]
Parameters
Type
Description
Default
callable
Function
Function to apply to each column or row
​
options
Object
axis: 0 or 1. If 0, compute the power column-wise, if 1, row-wise
{axis: 1}
Returns:
       return DataFrame
Examples
Apply a  function along default axis 1 (columns)
Note that the specified function passed to apply will be called with an array of the values across the specified axis.
Node
Browser
1
const dfd = require("danfojs-node")
2
​
3
let data = [[1, 2, 3], [4, 5, 6], [20, 30, 40], [39, 89, 78]]
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let cols = ["A", "B", "C"]
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let df = new dfd.DataFrame(data, { columns: cols })
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​
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function sum_vals(col) {
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    return col.reduce((a, b) => a + b, 0);
9
}
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​
11
let df_new = df.apply(sum_vals, { axis: 1 })
12
df_new.print()
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1
​
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Output
1
╔═══╤═════╗
2
║ A │ 64  ║
3
╟───┼─────╢
4
║ B │ 126 ║
5
╟───┼─────╢
6
║ C │ 127 ║
7
╚═══╧═════╝
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Apply a  function along  axis 0 (row)
Node
Browser
1
const dfd = require("danfojs-node")
2
​
3
let data = [[1, 2, 3], [4, 5, 6], [20, 30, 40], [39, 89, 78]]
4
let cols = ["A", "B", "C"]
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let df = new dfd.DataFrame(data, { columns: cols })
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​
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function sum_vals(col) {
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    return col.reduce((a, b) => a + b, 0);
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}
10
​
11
let df_new = df.apply(sum_vals, { axis: 0 })
12
df_new.print()
13
​
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1
​
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Output
1
╔═══╤═════╗
2
║ 0 │ 6   ║
3
╟───┼─────╢
4
║ 1 │ 15  ║
5
╟───┼─────╢
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║ 2 │ 90  ║
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╟───┼─────╢
8
║ 3 │ 206 ║
9
╚═══╧═════╝
10
​
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DataFrame.dropna

DataFrame.apply_map

Last modified 17d ago

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Contents

Examples

Apply a function along default axis 1 (columns)

Apply a function along axis 0 (row)