Pandas find columns with unique values
Use the Python library that allows you to query your database (pymysql, psycopg2, etc). Programmatically use the metadata available from the DB to iterate over the tables and columns. Dynamically create the SQL queries to compare "select count(field) - count(distinct field) from table". 
Or you could also potentially use the metadata to see which columns in each table are indexed.
The SQL query to pull the relevant metadata will vary based on the kind of DBMS.
I have two databases (each with 1000's of tables) which are supposed to reflect the same data but they come from two different sources. I compared two tables to see what the differences were, but to do that I joined the two on a common ID key. I checked the table manually to see what the ID key was, but when I have to check 1000's of tables its not practical to do so. 
Is there a way in pandas to find what column (or columns) in a table have only unique values?