擅长:python、mysql、java
<p>我宁愿保持简单并使用以下方法:</p>
<pre><code>book_dict = {"Book1" : {7:1,4:2}, "Book2" : {5:1,9:1,3:2,2:1}}
for k,v in book_dict.items():
print (k, v)
book_dict["Book1"][7] = book_dict["Book1"][7]+1
print (book_dict["Book1"])
book_dict["Book1"][8] = 1
print (book_dict["Book1"])
</code></pre>
<p>结果:</p>
<pre><code>Book1 {7: 1, 4: 2}
Book2 {5: 1, 9: 1, 3: 2, 2: 1}
{7: 2, 4: 2}
{7: 2, 4: 2, 8: 1}
</code></pre>