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

Expanding on the above use of EXISTS, I needed something to test table existence generally. I found that testing for results using fetch on a select statement yielded the result "None" on an empty existing table -- not ideal.

Here's what I came up with:

import psycopg2

def exist_test(tabletotest):

    schema=tabletotest.split('.')[0]
    table=tabletotest.split('.')[1]
    existtest="SELECT EXISTS (SELECT 1 FROM information_schema.tables WHERE table_schema = '"+schema+"' AND table_name = '"+table+"' );"

    print('existtest',existtest)

    cur.execute(existtest) # assumes youve already got your connection and cursor established

    # print('exists',cur.fetchall()[0])
    return ur.fetchall()[0] # returns true/false depending on whether table exists


exist_test('someschema.sometable')