python 2.7 code
cStr = \'\"aaaa\",\"bbbb\",\"ccc,ffffd\"\'
newStr = cStr.split(\',\')
print newStr
# result : [\'\"aaaa\"\',\'\"bbbb\"\',\'\"ccc\',\'ffffd\
You need a parser. You can build your own, or you may be able to press one of the library ones into service. In this case, json could be (ab)used.
import json
cStr = '"aaaa","bbbb","ccc,ffffd"'
jstr = '[' + cStr + ']'
result = json.loads( jstr) # ['aaaa', 'bbbb', 'ccc,ffffd']
result = [ '"'+r+'"' for r in result ] # ['"aaaa"', '"bbbb"', '"ccc,ffffd"']