convert to a list in python

Question

I have data with this shape

  [[array([list([35, 76, 987, 23]),
  list([76, 78, 54, 43]),
  list([2376, 768, 84, 43])],
  dtype=object)]]

I want to convert this data to a simple list like this

[35, 76, 987, 23, 76, 78, 54, 43, 2376, 768, 84, 43]

Answer 1

if your array is inside those 2d list, then you can use this:

from numpy import array
from itertools import chain

a = [[array([list([35, 76, 987, 23]),
         list([76, 78, 54, 43]),
         list([2376, 768, 84, 43])],
        dtype=object)]]
flat_list = list(chain(*a))
flat_list = (list(chain(*flat_list)))
flat_list = (list(chain(*flat_list)))

print(flat_list)

But I think your numpy array is like this:

a = array([list([35, 76, 987, 23]),
         list([76, 78, 54, 43]),
         list([2376, 768, 84, 43])],
        dtype=object)

then one time using of chain is enough like this:

flat_list = list(chain(*a))
    
print(flat_list)

Answer 2

The cryptic answer:

list([[np.array([list([35, 76, 987, 23]),
 list([76, 78, 54, 43]),
  list([2376, 768, 84, 43])],
  dtype=object)]][0][0].flatten())

Explanation:

from numpy import array
x = [[array([list([35, 76, 987, 23]),
  list([76, 78, 54, 43]),
  list([2376, 768, 84, 43])],
  dtype=object)]]

Note that x is a numpy array in a list, in a list. You may need to examine your life choices that have led you to arrive at this data structure :-)

Anyway, so x[0][0] is the numpy array that you actually want to get your hands on. Numpy arrays have the handy flatten() method, so:

x[0][0].flatten()
# -> array([35, 76, 987, 23, 76, 78, 54, 43, 2376, 768, 84, 43], dtype=object)

Now if you insist on getting a pure python list, just cast it like so:

list(x[0][0].flatten())
# -> [35, 76, 987, 23, 76, 78, 54, 43, 2376, 768, 84, 43]