code: def insertions_from_masked(seq):
      
      insertions = []
      prev = True
      for i, base in enumerate(seq):
          if base.isupper() and prev is True:
              insertions.append([])
              prev = False
          elif base.islower():
              insertions[-1].append(i)
              prev = True
      return [[min(i), max(i)] for i in insertions if i != []]
docs: get coordinates of insertions from insertion-masked sequence