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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 __meta_metadata(self, field, key):
 """Return the value for key for the field in the metadata"""

        mf = ''
        try:
            mf = str([f[key] for f in self.metadata
                     if f['field_name'] == field][0])
        except IndexError:
            print("%s not in metadata field:%s" % (key, field))
            return mf
        else:
            return mf