Empty List

[Christopher Reimer]

On 6/26/2016 8:13 PM, Elizabeth Weiss wrote:

> Hi There,
>
> What is the point of this code?:
>
> word=[]
> print(word)
>
> The result is []
>
> When would I need to use something like this?
>
> Thank you!

Sometimes you need to assign an empty list to a variable prior to using 
it in a looping structure.

Here's the load function from the BASIC interpreter/compiler I'm working 
on in Python.

def load(filename):
     tokens = []
     with open(filename) as source:
         for line in source:
             tokens.append(tokenizer(line))
     return tokens

Here's the BASIC file I'm loading:

10 PRINT "HELLO WORLD!"
20 GOTO 10

This function assigns an empty list to tokens, reads a line of text from 
a file, and appends a tokenized list to tokens, and return tokens as a 
list of lists.

[['10', 'PRINT', '"HELLO WORLD!"'], ['20', 'GOTO', '10']]

Chris R.