do this with list comp?

[Diez B. Roggisch]

John Hunter wrote:

> 
> I want to replace all empty fields in a CSV line with 'NULL'.
> 
> Here is a brute force way
> 
>     def fixline(line):
>         ret = []
>         for s in line.split(','):
>             if not len(s): ret.append('NULL')
>             else: ret.append(s)
>         return ret
> 
>     line = 'John,Bill,,,Fred'
>     print fixline(line)
>     # ['John', 'Bill', 'NULL', 'NULL', 'Fred']
> 
> I am wondering if there is a way to do it with list comprehensions.  I
> know how I would do it with a ternary operator.....

This should work:

res = [[s, 'NULL'][not len(s)] for s in line.split(",")]

Diez