A college thing.

classification.py

def bubble_sort(tuples):
    for iteration in range(len(tuples) - 1, 0, -1):
        for i in range(iteration):
            if tuples[i][1] > tuples[i + 1][1]:
                temp = tuples[i]
                tuples[i] = tuples[i + 1]
                tuples[i + 1] = temp
    return tuples


def lower(iterable):
    for i in range(len(iterable)):
        iterable[i] = iterable[i].lower()
    return iterable


commonWords = lower(["is", "the", "am"])

commonWords.append(".")

allWords = lower(["football", "is", "sport", "is", "game", "the", "sport", "football", "am", "sport"])

words = {}

for word in allWords:
    if word not in commonWords:
        if word in words:
            words[word] += 1
        else:
            words[word] = 1

print(words)

orderedWords = bubble_sort(list(words.items()))

print(orderedWords)

for i in range(len(orderedWords)):
    orderedWords[i] = orderedWords[i][0]

print(orderedWords)