DataFrame.applyMap

Apply a function to a Dataframe values element-wise.

danfo.DataFrame.applyMap(callable, options)

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}

Examples

Apply a function to each element in a DataFrame

Note that the specified function passed to applyMap will be called with each element in the DataFrame. If you need to apply a function across an axis, then use the apply function.

Node

const dfd = require("danfojs-node")

let data = {
    short_name: ["NG", "GH", "EGY", "SA"],
    long_name: ["Nigeria", "Ghana", "Eqypt", "South Africa"]
}
let df = new dfd.DataFrame(data)

function lower(x) {
    return `${x}`.toLowerCase()
}

let df_new = df.apply_map(lower)
df_new.print()

Browser

Output

╔════════════╤═══════════════════╤═══════════════════╗
║            │ short_name        │ long_name         ║
╟────────────┼───────────────────┼───────────────────╢
║ 0          │ ng                │ nigeria           ║
╟────────────┼───────────────────┼───────────────────╢
║ 1          │ gh                │ ghana             ║
╟────────────┼───────────────────┼───────────────────╢
║ 2          │ egy               │ eqypt             ║
╟────────────┼───────────────────┼───────────────────╢
║ 3          │ sa                │ south africa      ║
╚════════════╧═══════════════════╧═══════════════════╝