いしゃ
doctor
isha
JMdict 1159980
ちち父fatherはいしゃ医者doctorです
は (topic) raises the topic (父ちち (father)) — “as for my father…”. Japanese needs no verb here: the noun 医者いしゃ (doctor) simply names what the topic is, and polite です (is) closes the sentence. So the shape is just topic + noun + です (is).