Nested string to tuple python

Question

my String looks like:

"('f', ('d', ('a', 'b')), 'g')"

I want to convert that to tuple. How can do that... I will use that in drawing a dendogram

Edit: additional explanation: my code and output's (print's):

print type(myString)                     # <type 'str'>
print myString                           #('f',('d',('a','b')),'g')
myString = ast.literal_eval(myString)
print type(myString)                     #<type 'tuple'>
print myString                           #('f', ('d', ('a', 'b')), 'g')

for tuple in myString:                   #f
    print tuple                          #('d', ('a', 'b'))
                                         #g

Answer 1

You can do this with ast.literal_eval - for example:

>>> import ast
>>> s = "('f', ('d', ('a', 'b')), 'g')"
>>> ast.literal_eval(s)
('f', ('d', ('a', 'b')), 'g')

The documentation for that function says:

Safely evaluate an expression node or a string containing a Python expression. The string or node provided may only consist of the following Python literal structures: strings, numbers, tuples, lists, dicts, booleans, and None.

This can be used for safely evaluating strings containing Python expressions from untrusted sources without the need to parse the values oneself.

Answer 2

Use ast.literal_eval.

This will not let some malicious scripts run from the string provided as with eval.