<p>你看的不是字典格式,而是<a href="https://wiki.python.org/moin/TupleSyntax" rel="nofollow noreferrer">tuples</a>。你知道吗</p>
<blockquote>
<p>In Python, multiple-element tuples look like:</p>
<p><code>1,2,3</code></p>
<p>The essential elements are the commas between each element of the tuple. Multiple-element tuples may be written with a trailing comma, e.g.</p>
<p><code>1,2,3,</code></p>
<p>but the trailing comma is completely optional. Just like all other expressions in Python, multiple-element tuples may be enclosed in parentheses, e.g.</p>
<p><code>(1,2,3)</code></p>
<p>or</p>
<p><code>(1,2,3,)</code></p>
</blockquote>
<p>改用字符串格式:</p>
<pre><code>ex_dict={1:"how",3:"do you",7:"dotoday"}
for key in ex_dict:
print("{} and this is {}".format(key,ex_dict[key]))
</code></pre>
<p><strong>此外:</strong>您可以使用</p>
<pre><code>ex_dict={1:"how",3:"do you",7:"dotoday"}
for key, val in ex_dict.iteritems(): #ex_dict.items() in python3
print("{} and this is {}".format(key,val))
</code></pre>
<p><strong>最后:</strong>预先警告python中的字典有<a href="https://stackoverflow.com/questions/15479928/why-is-the-order-in-python-dictionaries-and-sets-arbitrary">arbitrary order.</a>如果您希望排序始终相同,那么使用<a href="https://docs.python.org/2/library/collections.html#collections.OrderedDict" rel="nofollow noreferrer">collections.OrderedDict</a>更安全。因为否则,您将依赖于实现细节。想亲眼看看吗?使<code>ex_dict = {1:"how",3:"do you",7:"dotoday", 9:"hi"}</code>。你知道吗</p>
<pre><code>import collections
ex_dict= collections.OrderedDict([(1,"how"),(3,"do you"),(7,"dotoday")])
for key, val in ex_dict.iteritems(): #ex_dict.items() in python3
print("{} and this is {}".format(key,val))
</code></pre>