Question

This is driving me crazy. I have a script that pulls data from a csv. For each row it makes it a list. The reason is I want to merge two items based on a command line argument.

Here is my list as an example:

row = ['city', 'state', 'zip', 'zippostal', 'company']

Well I know if I do a join on row[0] and row[2] I will get

row = ['citystatezip', 'zippostal', 'company']

Well what if I wanted this….

row = ['companycityzip', 'state', 'zippostal']

How could I do this?

Edit:

Im sorry I didnt mean to be brief. What I have is a csv file with a bunch of data sometimes the city state and zip is in different fields but I need to merge them either by a , or – depends on what is needed. So what I did was make them into a list and based on command line arguements selecting what columns they are in I need them to merge so Ex.

column a column b column c column d ……
city state zip code

I need to merge column a into b by a “,”. Well that works fine but sometimes column f will be the city and column a will be the state. So how to I merge them in a list and have both values end up in column a but still return the rest of the row minus the updated vaule.

Answer 1

Maybe something like this?:

>>> row = ['city', 'state', 'zip', 'zippostal', 'company']
>>> joins = [[4, 0, 2], [1], [3]]
>>> [''.join(row[i] for i in indices) for indices in joins]
['companycityzip', 'state', 'zippostal']

As a function:

def custom_join(row, *joins):
    return [''.join(row[i] for i in indices) for indices in joins]

Examples:

>>> row = ['city', 'state', 'zip', 'zippostal', 'company']
>>> custom_join(row, [0, 1, 2], [3], [4])
['citystatezip', 'zippostal', 'company']
>>> custom_join(row, [-1, 0, 2], [1], [-2])
['companycityzip', 'state', 'zippostal']

Edit: Here is a version that will return the remainder of the list after performing the joins:

def custom_join2(row, *joins):
    result = [''.join(row[i] for i in indices) for indices in joins]
    seen = set(i if i >= 0 else len(row)+i for indices in joins for i in indices)
    result.extend(v for i, v in enumerate(row) if i not in seen)
    return result

>>> custom_join2(row, [-1, 0, 2])
['companycityzip', 'state', 'zippostal']