The answer to a question on multiple-value elements in a config file (which exactly fits my needs) suggests to "unpack the string from the config". I read the doc for unpacking arguments lists suggested in several places but I fail to understand how this relates to my problem.
I am sure this must be obvious: having a string str = "123,456", how can I transform it into the list [123,456] (the number of elements separated by a comma in the string may vary)
Thank you.
[int(x) for x in str.split(",")] You're basically applying the function int to each element produced by split of your string.
The result of simply str.split(',') would be ["123","456"].
As Daniel Roseman pointed out, you should be careful not to use variable or method names that inadvertently overshadow built in methods, like, for instance, str.
Do you want a list of strings or a list of ints?
If you just want a list of strings, it's very simple:
my_list = my_string.split(',') If you want to convert these to ints, you need:
my_list = map(int, my_string.split(',')) (Also, don't use str as a variable name as it shadows the built-in str() function.)
map or simply the syntax I presented?
map this time because it's quicker to type :-)The easiest way would be to use split().
unpacked = str.split(',') Although I agree with the other answers, you should also handle exceptions in the case of invalid string representation of a supposed number. Take, for example, the following snippet:
number_string = "123,456,x21" delimiter = "," number_list = [] for item in number_string.split(delimiter): try: my_num = int(item) number_list.append(item) except ValueError, e: # you can choose to just pass or handle the error like so print "Skipping %s: %s" % (item, e.message) Just a thought. Good luck!
