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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 dict_to_querystring(dictionary):
 """Converts a dict to a querystring suitable to be appended to a URL."""

    s = u""
    for d in dictionary.keys():
        s = unicode.format(u"{0}{1}={2}&", s, d, dictionary[d])
    return s[:-1]