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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def pluralize(word):
 """ Return the plural form of a word. Examples:: "posts" "octopi" "sheep" "CamelOctopi" """

    if not word or word.lower() in UNCOUNTABLES:
        return word
    else:
        for rule, replacement in PLURALS:
            if re.search(rule, word):
                return re.sub(rule, replacement, word)
        return word