psycopg2 does not insert unicode data - postgresql

Question

I have a script that takes data from one database and according to tables' names and fields copies it into another database.
The issue is about unicode data, I need to insert some words in Russian but every time psycopg2 writes it as if it were default string.
import psycopg2
import psycopg2.extensions
conn_two = psycopg2.connect(user="postgres", password="password", host = "localhost", port= "5432", dbname = "base2")
cur_2 = conn_two.cursor()
sql = 'INSERT INTO {} ({}) VALUES {};'.format('"tb_names"', '"num", "name", "district"', (23, 'Рынок', 'Волжский'))
cur_2.execute(sql)
conn_two.commit()
Here is how the result looks like in pgAdmin4:
I also tried to set exteinsions and insert data in unicode, but in this case I have an error
import psycopg2
import psycopg2.extensions
psycopg2.extensions.register_type(psycopg2.extensions.UNICODE)
psycopg2.extensions.register_type(psycopg2.extensions.UNICODEARRAY)
conn_two = psycopg2.connect(user="postgres", password="password", host = "localhost", port= "5432", dbname = "base2")
conn_two.set_client_encoding("utf-8")
conn_two.set_client_encoding('UNICODE')
cur_2 = conn_two.cursor()
sql = 'INSERT INTO {} ({}) VALUES {};'.format('"tb_names"', '"num", "name", "district"', (23, u'Рынок', u'Волжский'))
cur_2.execute(sql)
conn_two.commit()
Traceback (most recent call last):
File "D:\_Scripts\pgadmin.py", line <>, in <module>
cur_2.execute(sql)
psycopg2.ProgrammingError: ОШИБКА: тип "u" не существует # - says that type "u" does not exist
LINE 1: ...ing_ex" ("num", "name", "district") VALUES (23, u'\u0420\u...
^
What should be done here?

Answer 1

Don't prepare your string with the values baked in (using string formatting or concatenation).
Instead, use %s in the SQL string as placeholders, then pass your values to the .execute method as an argument.
If you're on Python 2.x, non-ASCII strings should be passed as Unicode types.
E.g.
Python 2.x
sql = 'INSERT INTO "tb_names" ("num", "name", "district") VALUES (%s, %s, %s);'
cur_2.execute(sql, (23, u'Рынок', u'Волжский'))
Python 3.x
sql = 'INSERT INTO "tb_names" ("num", "name", "district") VALUES (%s, %s, %s);'
cur_2.execute(sql, (23, 'Рынок', 'Волжский'))