a = set(["Blah", "Hello"])
a = list(a)

TypeError: 'set' object is not callable

for item in set1:
    list.append(item)

>>> a = set(["Blah", "Hello"])
>>> a = list(a) # You probably wrote a = list(a()) here or list = set() above
>>> a
['Blah', 'Hello']

>>> assert isinstance(list, type)

>>> set=set()
>>> set=set()
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: 'set' object is not callable

>>> a=set()
>>> b=a()
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: 'set' object is not callable

a = set(["Blah", "Hello"])
a = list(a)
type(a)
<class 'list'>