I like to convert in a Python script the following string:
mystring='(5,650),(235,650),(465,650),(695,650)'
to a list of tuples
mytuple=[(5,650),(235,650),(465,650),(695,650)]
such that
print mytuple[0] yields:
(5,650)
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3 Answers
I'd use ast.literal_eval:
In [7]: ast.literal_eval('(5,650),(235,650),(465,650),(695,650)')
Out[7]: ((5, 650), (235, 650), (465, 650), (695, 650))
As seen above, this returns a tuple of tuples. If you want a list of tuples, simply apply list() to the result.
Comments
That's not a tuple, that's a list.
If you can depend on the format being exactly as you've shown, you can probably get away with doing something like this to convert it to a list:
mystring2 = mystring.translate(None, "()")
numbers = mystring2.split(",")
out = []
for i in xrange(len(numbers) / 2)
out.append((int(numbers[2 * i), int(2 * i + 1])))
This can probably be improved using some better list-walking mechanism. This should be pretty clear, though.
If you really really want a tuple of tuples, you can convert the final list:
out2 = tuple(out)
Comments
Use eval
mytuple = eval(mystring)
If you want a list enclose mystring with brackes
mytuble=eval("[%s]" % mystring)
That's the 'simplest' solution (nothing to import, work with Python 2.5)
However ast.literate_eval seems more appropriate in a defensive context.
2 Comments
glglgl
This would be my favourite - provided the string comes from a safe source. Otherwise, maybe a regex-based solution would be fine.
Moderator note: If you guys want to discuss the risks of using eval, please do so in chat. The comments under this answer have been removed because they degraded into noise. Removing just a few would have resulted in a broken conversation. Feel free to move it to chat, come to a resolution and then link to the transcript here.