Split a Python string with nested separated symbol

Question

I need from string

i = "1,'Test','items (one, two, etc.)',1,'long, list'"

extract array of next strings:

['1', "'Test'", "'items (one, two, etc.)'", '1', "'long, list'"]

with help of regexpress

r=re.split(r',+(?=[^()]*(?:\(|$))', i)

I receive next result only:

['1', "'Test'", "'items (one, two, etc.)'", '1', "'long", " list'"]

UPD1

NULL should be supported

i = "1,'Test',NULL,'items (one, two, etc.)',1,'long, list'"
['1', "'Test'", 'NULL', "'items (one, two, etc.)'", '1', "'long, list'"]

Answer 1

You don't need re.split in this case.you can use re.findall within a list comprehension :

>>> [k for j in re.findall(r"(\d)|'([^']*)'",i) for k in j if k]
['1', 'Test', 'items (one, two, etc.)', '1', 'long, list']

The preceding regex will match any thing between one quote '([^']*)' or any digit (\d).

Or as a more efficient way in this case you can use ast.literal_eval :

>>> from ast import literal_eval
>>> literal_eval(i)
(1, 'Test', 'items (one, two, etc.)', 1, 'long, list')

Answer 2

This is a task for the csv module:

import csv
from StringIO import StringIO
line = "1,'Test','items (one, two, etc.)',1,'long, list'"
reader = csv.reader(StringIO(line), quotechar="'")
row = next(reader)

# row == ['1', 'Test', 'items (one, two, etc.)', '1', 'long, list']

The key here is to create a CSV reader, specifying single quote as the quote character.