'str' object has no attribute 'intersection' and unhashable set

[meInvent bbird]

def consolidate(sets):
    # http://rosettacode.org/wiki/Set_consolidation#Python:_Iterative
    setlist = [s for s in sets if s]
    for i, s1 in enumerate(setlist):
        if s1:
            for s2 in setlist[i+1:]:
                intersection = s1.intersection(s2)
                if intersection:
                    s2.update(s1)
                    s1.clear()
                    s1 = s2
    return [s for s in setlist if s]

def wrapper(seqs):
    consolidated = consolidate(map(set, seqs))
    groupmap = {x: i for i,seq in enumerate(consolidated) for x in seq}
    output = {}
    for seq in seqs:
        target = output.setdefault(groupmap[seq[0]], [])
        target.append(seq)
    return list(output.values())

with open("testing1.txt", "r") as myfile:
    content = myfile.readlines()
    gr = [['']]
    for ii in range(0,500):
        try:
            gr = [[content[ii]]] + gr
        except:
            print "error" + str(content[ii])
    #groups = wrapper(content)
    for i, group in enumerate(wrapper(gr)):
        print('g{}:'.format(i), group)
        print("\n")

Traceback (most recent call last):
  File "<stdin>", line 10, in <module>
  File "<stdin>", line 2, in wrapper
  File "<stdin>", line 7, in consolidate
AttributeError: 'str' object has no attribute 'intersection'

>>> content[1]
'1,[(-1, 1, -2), (2, -1/2, 1)]\n'
>>> content[2]
'0,[(1, 0, 0)]\n'
>>> content[3]
'1,[(1, 0, 1)]\n'
>>> content[4]
'1,[]\n'
>>> content[5]
'1,[]\n'


then i try to edit to
gr = [[set(content[ii])]] + gr

it return unhashable type 'set'

just would like to search all repeatable pattern for a group of lines