[igsomething]

The map '%{username, age, first_name, last_name}' would be 1 character away from the tuple '{username, age, first_name, last_name}'. It is easy to miss the '%' character and you'll waste some time figuring out why your code is throwing match and/or function clause errors at runtime.

[Dkuku]

Using this logic [username, age first_name, last_name] is only 2 characters away. This example is easy to catch because tuple and map work completly different-it's not python.