[Tutor] Need to explicitly del a file object after reading contents?

[Jeff Kowalczyk]

I've been explicitly opening, reading, closing and deleting files when I
read their contents into variables. In these cases, I don't need
the file object kept around for anything. I do this mainly because I don't
know enough about when the garbage collector will delete the file object,
and I wouldn't want it left open until the gc happens.

Is it necessary to do this:

f = open(filepath,'r')
filestring = f.read()
f.close()
del f

vs. this?

filestring = open(filepath,'r').read()

The same filepath *may* be read or written in the next few seconds/minutes
by other code, but it usually won't happen. Is there a rule of thumb on
when to go with the explicit file management? Thanks.