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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(singular):
 """Convert singular word to its plural form. Args: singular: A word in its singular form. Returns: The word in its plural form. """

    if singular in UNCOUNTABLES:
        return singular
    for i in IRREGULAR:
        if i[0] == singular:
            return i[1]
    for i in PLURALIZE_PATTERNS:
        if re.search(i[0], singular):
            return re.sub(i[0], i[1], singular)