feat: add dataframe duolicated issue - #667 by RahulDas-dev · Pull Request #669 · javascriptdata/danfojs

This merge request adds a new [duplicated()] method to the DataFrame class that identifies duplicate rows within a DataFrame. This functionality is essential for data cleaning and exploration workflows.

// Create a DataFrame with duplicate rows
const df = new DataFrame({
  'A': [1, 2, 2, 3, 3],
  'B': ['a', 'b', 'b', 'c', 'c']
});

// Find duplicates keeping first occurrence (default)
const dups = df.duplicated();
// Returns: [false, false, true, false, true]

// Find duplicates keeping last occurrence
const dupsLast = df.duplicated({ keep: 'last' });
// Returns: [false, true, false, true, false]

// Find duplicates based on specific columns
const dupsSubset = df.duplicated({ subset: ['B'] });
// Returns: [false, false, true, false, true]