On 20 June 2010 19:38, Neil Thorman <neil.thor...@gmail.com> wrote: > I'm picking this up as a hobby really, not having done any programming > since Acorn I'm pretty much starting form scratch (and even back in the > BASIC day I never really got to grips with files). > This is from Alan Gauld's Learning to Program: Handling Files. > http://www.freenetpages.co.uk/hp/alan.gauld/ > > <http://www.freenetpages.co.uk/hp/alan.gauld/>Can I just check I'm getting > it? > > > *Menu.txt contains* > > *Spam & Eggs* > *Spam & Chips* > *Spam & Spam* > > >>>inp = file("menu.txt", "r") > *What is inp? What does it now contain?* > *The following creates a list;* >
inp is a file object. > * > * > * > >>>print inp.readlines() > ['spam & eggs\n', 'spam & chips\n', 'spam & spam'] > > * > readlines is a method of inp. It's basically a function that works specifically on that object, in this case it reads each line from the file and puts it into a list and then returns it; the shell then prints it out. > * > but if I do it again I get: > >>> print inp.readlines() > [] > > * > At this point you have reached the end of the file so there are no more lines to read, if you just want one line at a time then you should use inp.read() > * > I'm baffled, why is inp now empty? > * > inp isn't really empty it's still a file object there is just no data left to read. > * > > Many thanks > > Neil > > ps. I'm working in the IDLE Python Shell. > * >
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