Script to log on to a online vendor site automatically

The ideal sites are Amazon.com and Amazon,ca
We have the site URL, cart User-ID, cart password, amount of the shopping cart to be paid in a file.
The file has the Buyer name email address, delivery address, cart serious and password.
We have a second file with our corporate credit card information for Canada , the USA and India.
We want to run the script to
A log on to the site automatically. (It has bee suggested that this can be done in a windows terminal with a Python script and Send keys.
security issues will be afforested by the employee who is online
Once logged on I need the program to capture the amount of the sale in the shopping card. IF it matches the amount in the SP payment file
then
Select the payment options and add the delivery person and address from the file. file.
Pay for the goods
Wait for the confirmation
Save the page in the file.
Erase the credit card information.\
Log Out

We suggest using send keys and tabs to move around the Vendor website.
We need to add a c.