Skip to content
Deepbox
04beginner

DataFrame Basics

The basic DataFrame operations: creation, column access, selection, filtering, sorting, head and tail.

What you will learn

  • Use deepbox/dataframe for DataFrame, get, select, filter, sort, head, tail.
  • The basic DataFrame operations: creation, column access, selection, filtering, sorting, head and tail.

Source

index.ts
/** * Example 04: DataFrame Basics * * Basic DataFrame operations on tabular data: creation, column selection, * row filtering, sorting, and head/tail. */ import { DataFrame } from "deepbox/dataframe"; const expectNumber = (value: unknown): number => {  if (typeof value !== "number") {    throw new Error("Expected number");  }  return value;}; console.log("=== DataFrame Basics ===\n"); // Create a DataFrame from an object of column arrays. All columns must have the same length.const df = new DataFrame({  name: ["Alice", "Bob", "Charlie", "David", "Eve"],  age: [25, 30, 35, 28, 32],  salary: [50000, 60000, 75000, 55000, 70000],  department: ["IT", "HR", "IT", "Sales", "HR"],}); // Display the complete DataFrameconsole.log("Full DataFrame:");console.log(df.toString()); // Display DataFrame dimensionsconsole.log(`\nShape: ${df.shape[0]} rows x ${df.shape[1]} columns`); // Access individual columnsconsole.log("\nColumn Access:");console.log(`Columns: ${df.columns.join(", ")}\n`); // Get a single column as a Seriesconst ages = df.get("age");console.log("Age column:");console.log(`${ages.toString()}\n`); // Select several columns at once; the result is a DataFrameconst subset = df.select(["name", "salary"]);console.log("\nSelecting Multiple Columns:");console.log("Selected columns (name, salary):");console.log(`${subset.toString()}\n`); // Keep the rows for which the callback returns true (salary > 60000)const highEarners = df.filter((row) => expectNumber(row.salary) > 60000);console.log("Employees with salary > 60000:");console.log(`${highEarners.toString()}\n`); // Sort by one column. The second argument is "ascending", so false means descending.const sortedBySalary = df.sort("salary", false);console.log("\nSorting:");console.log("Sorted by salary (descending):");console.log(`${sortedBySalary.toString()}\n`); // Head and tailconsole.log("First 3 rows:");console.log(`${df.head(3).toString()}\n`); console.log("Last 2 rows:");console.log(`${df.tail(2).toString()}\n`); // Series values come back as a plain arrayconsole.log("Ages as an array:", ages.toArray());

Output

Console output
Console output only.