converting a string to a list of tuples

Question

I need to convert a string, '(2,3,4),(1,6,7)' into a list of tuples [(2,3,4),(1,6,7)] in Python. I was thinking to split up at every ',' and then use a for loop and append each tuple to an empty list. But I am not quite sure how to do it. A hint, anyone?

• eumiro: possible duplicate of Python convert formatted string to list

Answer 1

>>> list(ast.literal_eval('(2,3,4),(1,6,7)'))
[(2, 3, 4), (1, 6, 7)]

• soulcheck: +1 was about to post similar solution, but wrapping the string in [] and using eval. This looks much nicer.
• Linus Svendsson: I would like to do it without the ast.literal_eval.
• Linus Svendsson: because i haven't learnt about many of the built-in functions.. can you help?
• Sven Marnach: @LinusSvendsson: Then you have just learned about a new one. :) Well, anyway, when trying to provide a different solution, how would I know which function I am allowed to use, and which ones you would also reject?
• Sven Marnach: @LinusSvendsson: Sorry, I can't read your code. And the alleged result isn't correct Python syntax. Consider to edit your original question or ask a new one.

Answer 2

Without ast or eval:

def convert(in_str):
 result = []
 current_tuple = []
 for token in in_str.split(","):
 number = int(token.replace("(","").replace(")", ""))
 current_tuple.append(number)
 if ")" in token:
 result.append(tuple(current_tuple))
 current_tuple = []
 return result

Answer 3

Without ast:

>>> list(eval('(2,3,4),(1,6,7)'))
 [(2, 3, 4), (1, 6, 7)]

Answer 4

Just for completeness: soulcheck's solution, which meets the original poster's requirement to avoid ast.literal_eval:

def str2tupleList(s):
 return eval( "[%s]" % s )