word = [input("Enter the string: ")]

word1 = word.append[:1]

word2 = word[-2:]

word3= list(zip(word1,word2))

print(word3)

Enter the string: bbnnnvvv
Traceback (most recent call last):
File "C:/PythonApp/Python Project/strings2.3.py", line 5, in <module>
word1 = word.append[:1]
TypeError: 'builtin_function_or_method' object is not subscriptable