[Tutor] name 'x" is not defined

[Alan Gauld]

"carme colominas" <carme.colominas at gmail.com> wrote

> I'm a  linguist and absolut new on Python; I'm trying to follow the 
> first
> chapter of *Natural Language Processing in Python.

I'm not familiar witrh it but if the code you have is from the first
chapter then I suggest you should go through one of the beginner
Python tutorials first.

You don't say whether you know any other programjing languages
but from your question it doesn't look like it so I'll suggest you
try the Non Programmers tutorials:

http://wiki.python.org/moin/BeginnersGuide/NonProgrammers

> what does it mean that a function is not defined
> and how to proceed?

> Traceback (most recent call last):
>  File "<pyshell#47>", line 2, in <module>
>    if fdist(word)>= 3:
> NameError: name 'fdist' is not defined

Note that it doesn't say the function is not defined it says
the *name* is not defined.  That's a different thing. These
kinds of details matter in programming.

A name can be as variable or a function or a class or
a module or most any other kind of object in Python.
Names have to be created before they are used in Python.
In this case it is a function and we create it by defining
the function or by importing the function from another module.
The other possibility is to access it from another module
which we have already imported - like you did with the
words() function:

nltk.corpus.brown.words()

You may just need to preface the fdist() function with the
name of the module where it is defined.

But all of this will makemuch more sense if you go through
one of the tutorials on the link above.

-- 
Alan Gauld
Author of the Learn to Program web site
http://www.freenetpages.co.uk/hp/alan.gauld