Question

a = [{43:123}, {3:103}, {36:103}, {2:102}, {23:100}]

How can I extract id from it when each of the keys is id and value means a number of points.
I tried use this:

for b in a: 
     print a[i].keys()
     i+=1

Python result is a list, but I need integer type. eg
print a[2].keys() result [36] and I need 36 which is int. Thx

Answer 1

Access the first element from such list:

a[2].keys()[0]

or

next(a[2].iterkeys())

both returning the int 36.

To get a list of all keys:

[next(d.iterkeys()) for d in a]

returning [43, 3, 36, 2, 23]

Maybe you should convert your list of dicts into a simple dict:

d = {}
for x in a:
    d.update(x) 

obtaining {2: 102, 3: 103, 23: 100, 36: 103, 43: 123}, where you can get all keys with simple d.keys() and obtaining [3, 2, 43, 36, 23], although the order is not conserved.