search for a tuple value in a list of tuples

Question

My datastruture is actually a dictionary that has a integer key and a value that is a list of tuples. I want to find a particular index in that list. For example:

 d = {}
 d[2] = [(1,-2),(2,4),(3,2)]
 d[1] = [(1,-2),(1,4)]

I want to find all tuples in a list with index 2 or -2 (they can be in either first or second member of the tuple). Then based on certain conditions I want to remove tuple elements from the list. For example, I want to remove (1,-2) from the list d[2]. I did not find an efficient way to do this step because I also want to remove (1,-2) from the list d[1] whenever I remove it from d[2].

Answer 1

>>> a = [(1,1), (2,2)]
>>> if (1,1) in a:
...     print 'Ok'
... 
Ok
>>> 

---

To remove stuff:

>>> b = [(1,-1,(3,1),(5,2)]
>>> filter(lambda a: a != (1,-1), b)

Should give you:

[(3,1), (5,2)]

So..

d = {}
d[2] = [(1,-2),(2,4),(3,2)]
d[1] = [(1,-2),(1,4)]

for k, v in d.items():
    d[k] = filter(lambda a: a != (1,-1), v)

This will remove (1, -1) from your dictionary all entirely.