How can I convert a set to a list in Python? Using
a = set(["Blah", "Hello"]) a = list(a) doesn't work. It gives me:
TypeError: 'set' object is not callable 7 Answers
Your code does work (tested with cpython 2.4, 2.5, 2.6, 2.7, 3.1 and 3.2):
>>> a = set(["Blah", "Hello"]) >>> a = list(a) # You probably wrote a = list(a()) here or list = set() above >>> a ['Blah', 'Hello'] Check that you didn't overwrite list by accident:
>>> assert list == __builtins__.list You've shadowed the builtin set by accidentally using it as a variable name, here is a simple way to replicate your error
>>> set=set() >>> set=set() Traceback (most recent call last): File "<stdin>", line 1, in <module> TypeError: 'set' object is not callable The first line rebinds set to an instance of set. The second line is trying to call the instance which of course fails.
Here is a less confusing version using different names for each variable. Using a fresh interpreter
>>> a=set() >>> b=a() Traceback (most recent call last): File "<stdin>", line 1, in <module> TypeError: 'set' object is not callable Hopefully it is obvious that calling a is an error
before you write set(XXXXX) you have used "set" as a variable e.g.
set = 90 #you have used "set" as an object … … a = set(["Blah", "Hello"]) a = list(a) This will work:
>>> t = [1,1,2,2,3,3,4,5] >>> print list(set(t)) [1,2,3,4,5] However, if you have used "list" or "set" as a variable name you will get the:
TypeError: 'set' object is not callable eg:
>>> set = [1,1,2,2,3,3,4,5] >>> print list(set(set)) Traceback (most recent call last): File "<stdin>", line 1, in <module> TypeError: 'list' object is not callable Same error will occur if you have used "list" as a variable name.
s = set([1,2,3]) print [ x for x in iter(s) ] Your code works with Python 3.2.1 on Win7 x64
a = set(["Blah", "Hello"]) a = list(a) type(a) <class 'list'> Try using combination of map and lambda functions:
aList = map( lambda x: x, set ([1, 2, 6, 9, 0]) ) It is very convenient approach if you have a set of numbers in string and you want to convert it to list of integers:
aList = map( lambda x: int(x), set (['1', '2', '3', '7', '12']) ) 
