python - 如何遍历字典

Question

In [1]: test = {}

In [2]: test["apple"] = "green"

In [3]: test["banana"] = "yellow"

In [4]: test["orange"] = "orange"

In [5]: for fruit, colour in test:
   ....:     print(fruit)
   ....:     
---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
<ipython-input-32-8930fa4ae2ac> in <module>()
----> 1 for fruit, colour in test:
      2     print(fruit)
      3 

ValueError: too many values to unpack

我想要的是迭代 test 并将键和值放在一起。如果我只是执行 for item in test: 我只得到 key 。

最终目标的一个例子是:

for fruit, colour in test:
    print(f"The fruit {fruit} is the colour {colour}")

Answer 1

在 Python 2 中你会这样做:

for fruit, color in test.iteritems():
    # do stuff

在 Python 3 中，使用 items() 代替(iteritems() 已被删除):

for fruit, color in test.items():
    # do stuff

这包含在 the tutorial 中.