Checking if a postgresql table exists under python (and probably Psycopg2)

Question

How can I determine if a table exists using the Psycopg2 Python library? I want a true or false boolean.

Answer 1

I know you asked for psycopg2 answers, but I thought I'd add a utility function based on pandas (which uses psycopg2 under the hood), just because pd.read_sql_query() makes things so convenient, e.g. avoiding creating/closing cursors.

import pandas as pd

def db_table_exists(conn, tablename):
    # thanks to Peter Hansen's answer for this sql
    sql = f"select * from information_schema.tables where table_name='{tablename}'" 
    
    # return results of sql query from conn as a pandas dataframe
    results_df = pd.read_sql_query(sql, conn)

    # True if we got any results back, False if we didn't
    return bool(len(results_df))

I still use psycopg2 to create the db-connection object conn similarly to the other answers here.