Theano TypeError: function() takes at least 1 argument (1 given)

Question

One of my Theano functions does not take any inputs and only uses shared variables to calculate the output. But this function throws a TypeError: function() takes at least 1 argument (1 given) .

Here a minimal example:

import theano as th
import theano.tensor as T
import numpy as np

x, y = T.dscalars('x', 'y')
z = th.shared(np.zeros(2))

f1 = th.function(inputs=[x], updates=[(z, z+x)]) 
f2 = th.function(outputs=z)
f1(3)
print f2()


Traceback (most recent call last):
  File "/home/me/temp/theano.test.py", line 9, in <module>
    f2 = th.function(updates=[(z, z*z)])
TypeError: function() takes at least 1 argument (1 given)

Answer 1

From: https://stackoverflow.com/a/16782594/380038

" theano.function() always needs a list of inputs. If the function takes 0 input, like in this case, you need to give an empty list for the inputs."

f2 = th.function(outputs=z) has to be f2 = th.function([], outputs=z)