Not able insert batch using python's simple-salesforce butk insert  if data-list has atleast one invalid rocord

Not able insert batch using python's simple-salesforce butk insert  if data-list has atleast one invalid rocord

hi everyone,
I want to create a regex expression to match two strings
if one of the string is a match then regex will show success string else it will show error string, 
If my input equals to next OR prev it should show Success else Error
here I have created a regex but I am not sure  it is working

(?(?=next|prev) Success|Error)