'open' is not defined

[dieter]

<ltc.hotspot at gmail.com> writes:
> ...
> Why is open not defined in the following code:NameError: name 'open' is not defined
>
> Code reads as follows:
>
> fname = raw_input("Enter file name: ")
> if len(fname) < 1 : fname = "mbox-short.txt"
> fh = open(fname)
> count = 0
> for line in fh:
>     if not line.startswith('From'): continue
>     line2 = line.strip()
>     line3 = line2.split()
>     line4 = line3[1]
>     print line4
>     count = count + 1            
> print "There were", count, "lines in the file with From as the first word"

You might execute the code above in a "restricted execution environment"
(one where "__builtins__" is not the typical "__builtin__" module --
that's how "open" (and other builtins) is found).