os.walk/list

[ecu_jon]

yes i agree breaking stuff into smaller chunks is a good way to do it.
even were i to do something like

def safe_copy()
    f1=file(files ,'rb')
    f2 = file(os.path.join(currentdir,fname,files))
    truth = md5.new(f1.read()).digest() ==
    md5.new(f2.read()).digest()
    if truth == 0:
        print "file copy error"

that would probably work for the single file copy functions. but would
still breakdown during the for ...os.walk(), again because "fname" is
a list there, and the crypto functions work 1 file at a time. even
changing crypto functions wouldn't change that.