#0121

Label Encode Train and Test

MediumML25 min20 XP

Problem

Given train and test category lists, map sorted train categories to integer ids starting at 0. Unknown test categories should become -1. Return encoded_train, encoded_test, mapping.

Why This Matters

Encoders must be fit on training data and then applied consistently to validation/test data.

Function Signature

def label_encode_train_test(train, test):

Examples

Example 1

Inputtrain=["b","a","b"], test=["a","c"]

Output([1,0,1], [0,-1], {"a":0,"b":1})

c is unknown because it appears only in test.

Constraints

Return the requested value exactly.
Handle the stated edge cases.
Keep the solution readable.

CodePython

def label_encode_train_test(train, test):
    """
    Input example: train=["b","a","b"], test=["a","c"]
    Return: ([1,0,1], [0,-1], {"a":0,"b":1})
    Return the value from the function so the tests can compare it. Do not print unless the prompt asks.
    """
    # write your code here
    return [], [], {}

def label_encode_train_test(train, test):
    """
    Input example: train=["b","a","b"], test=["a","c"]
    Return: ([1,0,1], [0,-1], {"a":0,"b":1})
    Return the value from the function so the tests can compare it. Do not print unless the prompt asks.
    """
    # write your code here
    return [], [], {}

Visible browser tests run here when available.

Testcases1 visible / 3 hidden categories

Core example

Inputtrain=["b","a","b"], test=["a","c"]

Expected([1,0,1], [0,-1], {"a":0,"b":1})

c is unknown because it appears only in test.

Hidden Test Categories

empty testsingle train categoryunknown category