import re
rx = r"(?:[^][\\]|\\.)+|\[[^][]*]"
s = r"Lorem \[ipsum\] \\[dolor] sit amet"
results = re.findall(r'(?:[^][\\]|\\.)+|\[[^][]*]', s)
for result in results:
print("'{}'".format(result))
aW1wb3J0IHJlCnJ4ID0gciIoPzpbXl1bXFxdfFxcLikrfFxbW15dW10qXSIKcyA9IHIiTG9yZW0gXFtpcHN1bVxdIFxcW2RvbG9yXSBzaXQgYW1ldCIKcmVzdWx0cyA9IHJlLmZpbmRhbGwocicoPzpbXl1bXFxdfFxcLikrfFxbW15dW10qXScsIHMpCmZvciByZXN1bHQgaW4gcmVzdWx0czoKCXByaW50KCIne30nIi5mb3JtYXQocmVzdWx0KSkK