modifying the origin of an iterator

[Skaperen]

suppose i call iter() to create an iterator from a large list. if i subsequently modify that list, will that impact that iterator or is an iterator from iter() completely independent, such as by making a copy of the origin object passed in the call to iter()?

based on readings of the python documentation, it appears that the data object is used, but it does not indicate if that is a copy or not.