Replacing comma when surrounded by words from list-CodePudding

I have a CSV file where one of the columns itself contains a list of words separated by commas. I want to take that list of words and replace the commas with a hyphen.

For example, if my list of words is ["Snow", "Wet"], and my line is:

value1, value2, Wet, Snow, value3

I'd like to have

value1, value2, Wet-Snow, value3

I almost know how to do this with sed, but it's giving me funky results. It seems ideal for a python regex, but I can't get it to work.

CodePudding user response：

Here's a split-and-loop solution:

words = ["Snow","Wet"]
def transform(src):
    parts = src.split(", ")
    out = []
    for word in parts:
        if word in words:
            if second:
                word = out.pop() '-' word
            second = True
        else:
            second = False
        out.append(word)
    return ', '.join(out)

print( transform( "value1, value2, Wet, Snow, value3" ) )

Output:

value1, value2, Wet-Snow, value3

CodePudding user response：

IIUC, one way using itertools.groupby:

from itertools import groupby

keys = {"Snow", "Wet"}
l = ['value1', 'value2', 'Wet', 'Snow', 'value3']

["-".join(g) for _, g in groupby(l, key=lambda x: (x in keys) or x)]

Output:

['value1', 'value2', 'Wet-Snow', 'value3']