Supplementary dictionary

Button keys (), the value of values ​​(), on the key-value items ()

# dic之键keys()、值values()、键值对items()，python2中取出的是列表（鸡蛋）；python3中取出的是元组（鸡）

dic = {'a': 1, 'b': 2}

print(f"dic.keys(): {dic.keys()}")
print(f"dic.values(): {dic.values()}")
print(f"dic.items(): {dic.items()}")
dic.keys(): dict_keys(['a', 'b'])
dic.values(): dict_values([1, 2])
dic.items(): dict_items([('