a = [ 1, 2, 3]
b = a[1:]
 
print("Exemplo1...")
print("Antes da modificação a[1] = 'teste':")
print(*b)
a[1] = "teste"
print("\nApós modificação a[1] = 'teste':")
print(*b)
 
print("Exemplo2...")
from collections.abc import Sequence
 
class BasicListView(Sequence):
  def __init__(self, seq, start=0, stop=None, step=1):
    self._seq = seq
    self._start = start    
    self._stop = len(seq)-1 if stop is None else stop
    self._step = step
 
  def __len__(self):
    return (self._stop - self._start) // self._step
 
  def __getitem__(self, key):
    k = self._step * key + self._start    
    return self._seq[k]
 
 
a = [ 1, 2, 3]
b = BasicListView(a,1,3)
 
print("Antes da modificação a[1] = 'teste':")
print(*b)
a[1] = "teste"
print("\nApós modificação a[1] = 'teste':")
print(*b)

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