LineEncoders

encoders.py

import abc


class LineEncoder:

    def __init__(self, algorithm):
        self.algorithm = algorithm

    def encode(self, text):
        words = text.split(" ")
        result = []
        for word in words:
            result.append(self.algorithm.encode_word(word))
        return " ".join(result)


class Reverser:

    def encode_word(self, word):
        return word[::-1]


class Doubler:

    def encode_word(self, word):
        return word + word

encoders_test.py

from encoders import Reverser, Doubler, LineEncoder


def test_can_reverse_a_single_word():
    assert LineEncoder(Reverser()).encode("abcd") == "dcba"


def test_can_reverse_each_word_in_line():
    assert LineEncoder(Reverser()).encode("abcd 123") == "dcba 321"


def test_can_double_a_single_word():
    assert LineEncoder(Doubler()).encode("abcd") == "abcdabcd"


def test_can_double_each_word_in_line():
    assert LineEncoder(Doubler()).encode("abcd 123") == "abcdabcd 123123"