What variable type is returned from Open()?

[dcwhatthe at gmail.com]

Hi,


As much as possible, I make use of optional type hints.  So if I know a function returns an integer, then I use


this_number_i : int = GetThisNumber()


But there's no 'file' type, so I'm not sure what to use as the type for the return value of an Open() function.


config_file : file = open(config_file_s, "r")


What type of variable should config_file (above) be declared as?