Flattening 1D and 2D list

Language Help Python
1

I’m trying to flatten a 2D list in python. The major issue is it looks something like this:
[a, b, c, [d, e, f, g, h], i, [j, k], etc]

since this is a mixture of a 1D and 2D list, how can I flatten it to:
[a, b, c, d, e, f, g, h, i, j, k, etc]

my current attempt looks something like this:


def flatten(array):
	test = []
	for i in range(len(array)):
		try:
			if array[i][0]:
				for r in range(array[i]):
					test.append(array[i][r])
		except:
			test.append(array[i])
	return(test)