<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def pretty_print(self, as_list=False, show_datetime=True):
 """ Return a Unicode string pretty print of the log entries. :param bool as_list: if ``True``, return a list of Unicode strings, one for each entry, instead of a Unicode string :param bool show_datetime: if ``True``, show the date and time of the entries :rtype: string or list of strings """

        ppl = [entry.pretty_print(show_datetime) for entry in self.entries]
        if as_list:
            return ppl
        return u"\n".join(ppl)