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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 days(start, end=None):
 """Iterate over the days between the given datetime_tzs. Args: start: datetime_tz to start from. end: (Optional) Date to end at, if not given the iterator will never terminate. Returns: An iterator which generates datetime_tz objects a day apart. """

    return iterate.between(start, datetime.timedelta(days=1), end)