Script to push data from one database via api to another
A few notes on your code above:


connect_mssqlserver and connect_mysqlserver could be condensed to a single 'connect' function that takes a conn_str arg to be used in create_engine.
I believe create_df seems to be unnecessary at this point. If the process for creating the df involves more than just calling read_sql in the future, then I would opt for moving that logic into a separate function.
nitpick: I would change source_df.empty == False and the following True check to just not source.empty and dest_df.empty