flattening-lists.py

# Need to install the package - iteration_utilities using 
#   ```$ pip3 install iteration_utilities```

from iteration_utilities import deepflatten

# if you only have one depth nested_list, use this
def flatten(l):
    return [item for sublist in l for item in sublist]

l = [[1,2,3],[3]]
print(flatten(l))
# [1, 2, 3, 3]

# if you don't know how deep the list is nested
l = [[1,2,3],[4,[5],[6,7]],[8,[9,[10]]]]

print(list(deepflatten(l, depth=3)))
# [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]