Strange change in the output

Question

The code:
https://www.sololearn.com/en/compiler-playground/cmqaTR3LvPJd

The output:
{(1, 2): 'list', 'value': 'one'}
dict_keys([(1, 2), 'value'])
dict_values(['list', 'one'])
dict_items([((1, 2), 'list'), ('value', 'one')])

Where did dict_ come from? I expected to see the variable name instead.

Answer 1

these are the object types.

Answer 2

There was no mention of them in the lesson about dictionaries.