Convert list to tuple in Python

It should work fine. Don't use tuple, list or other special names as a variable name. It's probably what's causing your problem.

>>> l = [4,5,6]
>>> tuple(l)
(4, 5, 6)

>>> tuple = 'whoops'   # Don't do this
>>> tuple(l)
TypeError: 'tuple' object is not callable

Expanding on eumiro's comment, normally tuple(l) will convert a list l into a tuple:

In [1]: l = [4,5,6]

In [2]: tuple
Out[2]: <type 'tuple'>

In [3]: tuple(l)
Out[3]: (4, 5, 6)

However, if you've redefined tuple to be a tuple rather than the type tuple:

In [4]: tuple = tuple(l)

In [5]: tuple
Out[5]: (4, 5, 6)

then you get a TypeError since the tuple itself is not callable:

In [6]: tuple(l)
TypeError: 'tuple' object is not callable

You can recover the original definition for tuple by quitting and restarting your interpreter, or (thanks to @glglgl):

In [6]: del tuple

In [7]: tuple
Out[7]: <type 'tuple'>

You might have done something like this:

>>> tuple = 45, 34  # You used `tuple` as a variable here
>>> tuple
(45, 34)
>>> l = [4, 5, 6]
>>> tuple(l)   # Will try to invoke the variable `tuple` rather than tuple type.

Traceback (most recent call last):
  File "<pyshell#10>", line 1, in <module>
    tuple(l)
TypeError: 'tuple' object is not callable
>>>
>>> del tuple  # You can delete the object tuple created earlier to make it work
>>> tuple(l)
(4, 5, 6)

Here's the problem... Since you have used a tuple variable to hold a tuple (45, 34) earlier... So, now tuple is an object of type tuple now...

It is no more a type and hence, it is no more Callable.

Never use any built-in types as your variable name... You do have any other name to use. Use any arbitrary name for your variable instead...

I find many answers up to date and properly answered but will add something new to stack of answers.

In python there are infinite ways to do this, here are some instances
Normal way

>>> l= [1,2,"stackoverflow","python"]
>>> l
[1, 2, 'stackoverflow', 'python']
>>> tup = tuple(l)
>>> type(tup)
<type 'tuple'>
>>> tup
(1, 2, 'stackoverflow', 'python')

smart way

>>>tuple(item for item in l)
(1, 2, 'stackoverflow', 'python')

Remember tuple is immutable ,used for storing something valuable. For example password,key or hashes are stored in tuples or dictionaries. If knife is needed why to use sword to cut apples. Use it wisely, it will also make your program efficient.