file bug???

[Bengt Richter]

On Thu, 20 Nov 2003 22:52:40 -0500, hokiegal99 <hokiegal99 at hotmail.com> wrote:

>When I use 'file' instead of 'open' on the 4th line of this script (the 
>line that begins with "outputFile") I get this error: 
>"UnboundLocalError: local variable 'file' referenced before assignment" 
>'open' works w/o problem and 'file' works in some other scripts that are 
>almost identical to this one... any ideas? I can post a script where 
>'file' works if anyone is interested.

No, UIAM this is a good lesson on why it's not a good idea to use names of builtins as
variable names.
>
>import os, string
>setpath = raw_input("Enter the path to the Mac files and folders: ")
>def clean_spaces(setpath):
>    outputFile = open('fix-spaces.txt', 'w')
                  ^^^^-- file would be fine here if you didn't shadow the name below
>    for root, dirs, files in os.walk(setpath):
>        for dir in dirs:
>            old_dname = dir
>            new_dname = old_dname.strip()
>            if new_dname != old_dname:
>                newpath = os.path.join(root,new_dname)
>                oldpath = os.path.join(root,old_dname)
>                print >> outputFile, "Replaced   ", old_dname, "\nWith 
>       ", new_dname
>                os.rename(oldpath,newpath)
>        for file in files:
             ^^^^ this is effectively an assignment in the local scope, so the compiler
                  thinks 'file' is a local variable (which it actually becomes because of this).
                  That means that 'file' in the place of 'open' above can't be referring
                  to the intended builtin, and so it looks like it's referring to the 'file'
                  variable you assign here, but before it's assigned.
                  Try using a different name, e.g.,
         for a_file in files:
>            old_fname = file
             old_fname = a_file
>            new_fname = old_fname.strip()
>            if new_fname != old_fname:
>                newpath = os.path.join(root,new_fname)
>                oldpath = os.path.join(root,old_fname)
>                print >> outputFile, "Replaced   ", old_fname, "\nWith 
>       ", new_fname
>                os.rename(oldpath,newpath)
>    outputFile.close()
>clean_spaces(setpath)
>

Regards,
Bengt Richter