There's this built-in python module, we'll call it mystery.
Now, mystery has this function, we'll call it ted.
Also, mystery has another function, we'll call it jan.
Finally, lets bring Thomas into the equation, your typical python programmer.

One day, Thomas goes

import mystery

print(mystery.ted('Hello world.'...

The program runs with no error, and ted gives him a message. "Very mysterious..." Thomas thinks.

Days later Thomas goes

import mystery

print(mystery.jan('Hello world.'...

The program runs with no error, and jan gives him a message. At fist Thomas doesn't think much of it... until HE REMEMBERS TED! He goes pale. "Is someone or something trying to tell me something?" he thinks.

Thomas decides to tell ted what jan said, cause obviously ted would be interested. No errors, but ted's answer have Thomas shocked! "He... he's alive..." he realizes.

What is this mysterious module? Will ted and jan take over the world?

No, seriously, find out what this so-called "mystery" module is called in real life, for example, "os", and also explain what functions "ted" and "jan" are.

Note: when Thomas first called mystery.ted() and mystery.jan(), he put the exact same parameters into the brackets.

Hint:

If you've joined SO and PSE, this module is for you!

Hint (2):

This involves code right?