parameterized full text search problem

I want the user to be able to pass in the search term at runtime, something akin to:
search_term = input(Search Payee: )
cur.execute("""SELECT * FROM entity WHERE to_tsvector(%s, entity_name) @@ to_tsquery(%s, %s);""",
        ("english" "english", search_term))

Running the script at the command line, I get:
python3 dbconnect_test.py
Search for Payee: compare foods
Traceback (most recent call last):
  File "dbconnect_test.py", line 46, in <module>
    main()
  File "dbconnect_test.py", line 27, in main
    ("english", "english", search_term))
psycopg2.ProgrammingError: syntax error in tsquery: "compare foods"

I tried this approach (from the example in the documentation, using %(str)s in place of %s:
cur.execute("""SELECT * FROM entity WHERE to_tsvector(%(str)s, entity_name) @@ to_tsquery(%(str)s, %(str)s);""",
        {'str': "english", 'str': "english", 'str': search_term})

With this result:
Search for Payee: compare foods  # I enter a search term
Traceback (most recent call last):
  File "dbconnect_test.py", line 46, in <module>
    main()
  File "dbconnect_test.py", line 27, in main
    {'str': "english", 'str': "english", 'str': search_term})
psycopg2.ProgrammingError: invalid name syntax
LINE 1: SELECT * FROM entity WHERE to_tsvector('compare foods', enti...

Clearly, I am missing something, but am not sure what.  I greatly appreciate any help I can get on this.

Thanks,
Don

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D.C. Parris, FMP, Linux+, ESL Certificate
Minister, Security/FM Coordinator, Free Software Advocate