python - TypeError: 'set' object has no attribute '__getitem__' -


i trying create list of lists using recursion in python.

for example:

   li = [1,2,3,4,5] // given list     listoflists = [[1,2,3,4,5],[2,3,4,5],[3,4,5],[4,5],[5]]//required list   def recur(li,index,perlist):     if(index==3):        return     else:       templi = li[index:len(li)]       perlist.append(templi)       recur(li,index+1,perlist)  li = {1,2,3} perlist = [] recur(li,0,perlist) print perlist

it throws following error:

typeerror: 'set' object has no attribute '__getitem__'

as other users have pointed out, lists made [] brackets.

def recur(li,index,perlist):     if(index==3):        return     else:       templi = li[index:len(li)]       perlist.append(templi)       recur(li,index+1,perlist)  li = [1,2,3] perlist = [] recur(li,0,perlist) print perlist

works fine, giving output 

[[1, 2, 3], [2, 3], [3]]

the {} brackets may habit c-like language, in python, list of items in {} brackets set (hashset). important distinction set unordered, , used membership testing, whereas list ordered, , supports indexing , iteration. "has no attribute '__getitem__'" means set not support indexing. has l[0] becoming l.__getitem__(...). note {} brackets used making dicts (hashmap, associative array..), that's colon -

in more demonstrative terms:

>>> = {1, 2, 3} >>> b = [1, 2, 3] >>> c = {1: "x", 2: "y", 3: "z"}

a set,

b list,

c dict


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