I basically want a python equivalent of this in C:
int a[x];
but in python I declare an array like:
a = []
<
You can use numpy:
import numpy as np
Example from Empty Array:
np.empty([2, 2])
array([[ -9.74499359e+001, 6.69583040e-309],
[ 2.13182611e-314, 3.06959433e-309]])
If you actually want a C-style array
import array
a = array.array('i', x * [0])
a[3] = 5
try:
[5] = 'a'
except TypeError:
print('integers only allowed')
Note that there's no concept of un-initialized variable in python. A variable is a name that is bound to a value, so that value must have something. In the example above the array is initialized with zeros.
However, this is uncommon in python, unless you actually need it for low-level stuff. In most cases, you are better-off using an empty list or empty numpy array, as other answers suggest.