Python list syntax help

Question

results=[key for key, value in adictionary if str(key).startswith('target') 
    and value > 0 ]

What am I trying to do here is select all the keys if the key in dictionary that beginswith target and its value is greater than 0. But looks there's a problem with this, help me~

Answer 1

results=[key for key, value in adictionary.items() if str(key).startswith('target') 
             and value > 0 ]

Answer 2

Missing items() ior iteritems() to your dict access. iteritems will not create a temp list which could be slightly faster.

results=[key for key, value in adictionary.iteritems() if str(key).startswith('target') 
             and value > 0 ]

Answer 3

You need to use the items() method to get both key and value.

 [key for key, value in adictionary.items() if str(key).startswith('target') and value > 0]

Answer 4

startswith() is slower than slicing

I would do:

results=[k for k,v in adictionary.iteritems()
         if (k[0:7]=='target')==True==(v>0)]

Answer 5

I'd use the iteritems() method of the dictionary. It returns an interator rather than generating a full list like the items() method does.

results = [key for key, value in adictionary.iteritems() if str(key).startswith('target') and value > 0]