Is it possible to give custom functions access to the Book object model?

[fzumstein]

In classic UDFs, you can call do something like

import xlwings as xw

@xw.func
def get_fullname():
    book = xw.Book.caller()
    return book.fullname

but this may not easily translate to custom functions. Maybe custom functions with side-effects (see hello_with_script() sample) might be a workaround though.