>>> int("99 years ago.")
Traceback (most recent call last):
? File "<stdin>", line 1, in <module>
ValueError: invalid literal for int() with base 10: '99 years ago.'

>>> demo = {"China": "Beijing", "Japan": "Tokyo"}
>>> for k, v in demo:
... ? ? print(k, v)
...
Traceback (most recent call last):
? File "<stdin>", line 1, in <module>
ValueError: too many values to unpack (expected 2)

>>> demo = {"China": "Beijing", "Japan": "Tokyo"}
>>> for key in demo:
... ? ? print(key, demo[key])
...
China Beijing
Japan Tokyo

>>> demo = {"China": "Beijing", "Japan": "Tokyo", "the United States": "Washington D.C."}
>>> for key, value in demo.items():
... ? ? print(key, value)
...
China Beijing
Japan Tokyo
the United States Washington D.C.
ValueError: binary mode doesn't take an encoding argument

>>> with open("protoc-gen-go", "rb+", encoding="utf-8") as file:
... ? ? data = file.read()
...
Traceback (most recent call last):
? File "<stdin>", line 1, in <module>
ValueError: binary mode doesn't take an encoding argument

>>> with open("protoc-gen-go", "rb+") as file:
... ? ? data = file.read(10)
...
>>> data
b'\xcf\xfa\xed\xfe\x07\x00\x00\x01\x03\x00'