Extract tuples from space separated string of tuples.

[sudeepto]

I have string in the following form:

 my_string = '(1, 2) (3, 4)'

As you can see, the tuples inside the string are space separated. I want to know how can I extract those tuples into separate variables.

[bvdet]

There may be a better way.

>>> my_string = '(1, 2) (3, 4)'
>>> eval(my_string.replace(") (", "),("))
((1, 2), (3, 4))
>>> a,b = eval(my_string.replace(") (", "),("))
>>> a
(1, 2)
>>> b
(3, 4)
>>>

[sudeepto]

Thank you bvdet. But I have a question.

Can you please explain me what is happening in the code ?? I have never used eval function in Python.

Also I have read that using eval is not recommended in Python. Can you tell me why is that ??

EDIT: I used your approach of substituting the

) (

part with

), (

so that I get the string

(1, 2), (3, 4)

Then after that, I searched on StackOverflow about ast module and literal_eval function.

converting-string-to-tuple

I used it to separate the tuples into variables.

Thank You for the help .

[bvdet]

Built-in funcation eval: Python documentation for eval

The function could potentially evaluate malicious code, therefore its use if sometimes frowned upon. A regex solution could potentially be a more robust but complicated solution.

>>> import re
>>> re.compile("[(](\d+, \d+)[)]")
<_sre.SRE_Pattern object at 0x0000000005C3EA80>
>>> pattern = re.compile("[(](\d+, \d+)[)]")
>>> pattern.findall('(1, 2) (3, 4)')
['1, 2', '3, 4']
>>> ((int(i) for i in item.split(",")) for item in pattern.findall('(1, 2) (3, 4)'))
<generator object <genexpr> at 0x0000000005E7CD38>
>>> for obj in ((int(i) for i in item.split(",")) for item in pattern.findall('(1, 2) (3, 4)')):
... 	print tuple(obj)
... 	
(1, 2)
(3, 4)
>>>