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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 strip_key_strings(pofile):
 """ Removes all entries in PO which are key strings. These entries should appear only in messages.po, not in any other po files. """

    newlist = [entry for entry in pofile if not is_key_string(entry.msgid)]
    del pofile[:]
    pofile += newlist