isinstance(.., file) for Python 3

[Duncan Booth]

Ulrich Eckhardt <ulrich.eckhardt at dominolaser.com> wrote:

> If possible, I'm looking for a solution that works for Pythons 2 and 3, 
> since I'm not fully through the conversion yet and have clients that 
> might use the older snake for some time before shedding their skin.
> 
> Suggestions?

Why bother checking types at all?

def foo(file_or_string):
    try:
        data = file_or_string.read()
    except AttributeError:
        data = file_or_string
    ... use data ...

-- 
Duncan Booth http://kupuguy.blogspot.com