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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 extract_geo(self):
        '''
        Extract geo-related information from exif
        '''
        altitude = self.extract_altitude()
        dop = self.extract_dop()
        lon, lat = self.extract_lon_lat()
        d = {}
        if lon is not None and lat is not None:
            d['latitude'] = lat
            d['longitude'] = lon
        if altitude is not None:
            d['altitude'] = altitude
        if dop is not None:
            d['dop'] = dop
        return d