可以使用 [key] 的方式来访问字典中的项，比如获取下面字典中的 key=model 的值，代码如下：
thisdict = {
"brand": "Ford",
"model": "Mustang",
"year": 1964
}
x = thisdict["model"]
print(x)
PS E:dreammarkdownpython> & "C:/Program Files (x86)/Python/python.exe" e:/dream/markdown/python/app/app.py
Mustang
当然除了中括号，还可以使用 get() 方法来访问，如下代码所示:
x = thisdict.get("model")
要想获取字典中的所有 keys，可以直接调用 dict 的 keys() 方法即可。
thisdict = {
"brand": "Ford",
"model": "Mustang",
"year": 1964
}
keys = thisdict.keys()
print(keys)
PS E:dreammarkdownpython> & "C:/Program Files (x86)/Python/python.exe" e:/dream/markdown/python/app/app.py
dict_keys(['brand', 'model', 'year'])
除了可以获取 dict 中的 keys，还可以通过 values() 获取 dict 中的所有value，如下代码所示：
thisdict = {
"brand": "Ford",
"model": "Mustang",
"year": 1964
}
keys = thisdict.values()
print(keys)
PS E:dreammarkdownpython> & "C:/Program Files (x86)/Python/python.exe" e:/dream/markdown/python/app/app.py
dict_values(['Ford', 'Mustang', 1964])
上面的方法分别从 dict 中获取 keys 或者 values,这一节我们调用 items() 获取字典中的 key-value 集合，如下代码所示:
thisdict = {
"brand": "Ford",
"model": "Mustang",
"year": 1964
}
items= thisdict.items()
print(items)
PS E:dreammarkdownpython> & "C:/Program Files (x86)/Python/python.exe" e:/dream/markdown/python/app/app.py
dict_items([('brand', 'Ford'), ('model', 'Mustang'), ('year', 1964)])
要想判断字典中是否存在某一个 key，可以用 python 内置的 in 操作符即可，如下代码所示：
thisdict = {
"brand": "Ford",
"model": "Mustang",
"year": 1964
}
if "model" in thisdict:
print("Yes, 'model' is one of the keys in the thisdict dictionary")
PS E:dreammarkdownpython> & "C:/Program Files (x86)/Python/python.exe" e:/dream/markdown/python/app/app.py
Yes, 'model' is one of the keys in the thisdict dictionary
