Bifurcate List Based on Function

Introduction

In this challenge, you will write a Python function that splits a list into two groups based on the result of a given filtering function. This is a common task in programming, especially when dealing with large datasets.

Bifurcate List Based on Function

Write a function bifurcate_by(lst, fn) that takes a list lst and a filtering function fn as arguments. The function should split the list into two groups based on the result of the filtering function. If the filtering function returns a truthy value for an element, it should be added to the first group. Otherwise, it should be added to the second group.

Your function should return a list of two lists, where the first list contains all the elements for which the filtering function returned a truthy value, and the second list contains all the elements for which the filtering function returned a falsy value.

Use a list comprehension to add elements to groups, based on the value returned by fn for each element.

def bifurcate_by(lst, fn):
  return [
    [x for x in lst if fn(x)],
    [x for x in lst if not fn(x)]
  ]

bifurcate_by(['beep', 'boop', 'foo', 'bar'], lambda x: x[0] == 'b')
## [ ['beep', 'boop', 'bar'], ['foo'] ]

Summary

In this challenge, you learned how to split a list into two groups based on the result of a given filtering function. You used a list comprehension to add elements to groups, based on the value returned by the filtering function for each element. This is a useful technique in programming, especially when dealing with large datasets.