do this with list comp?

[Michael T. Babcock]

python-list-request at python.org wrote:

>
> Subject:
> do this with list comp?
> From:
> John Hunter <jdhunter at ace.bsd.uchicago.edu>
> Date:
> Fri, 12 Dec 2003 10:46:58 -0600
> To:
> python-list at python.org
>
>
>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.....
>  
>

def replace_blank_with_null(data):
    if not data:
       return "NULL"
    return data

new_list = [ replace_blank_with_null(line) for line in old_list ]

Or something more like:

line_items = [ replace_blank_with_null(item) for item in line.split(",") ]

-- 
Michael T. Babcock
C.T.O., FibreSpeed Ltd.
http://www.fibrespeed.net/~mbabcock