<p>我需要创建一个嵌套列表,四层深。在第四个层面,我需要系统地分配价值观。当第四个级别处于其第一个循环的中间时,无论指定的值是什么,都会出现索引错误,正如您在代码下面的输出中看到的那样。在</p>
<pre><code> fourNest = [ [[[[[AA, BB, CC, DD]
for AA in range(2)]
for BB in range(3)]
for CC in range(4)]
for DD in range(5)]]
print fourNest #this prints as expected and assignments work manually
for AA in range(2):
print "AA = ", AA
for BB in range(3):
print " BB = ", BB
for CC in range(4):
print " CC = ", CC
for DD in range(5):
fourNest[AA][BB][CC][DD] = 1
print " DD = ", DD," ", fourNest[AA][BB][CC][DD]
</code></pre>
^{pr2}$
<pre><code>Traceback (most recent call last):
File "C:/Python27/forListCreateTest", line 21, in <module>
fourNest[AA][BB][CC][DD] = 1
IndexError: list assignment index out of range
</code></pre>
<p>LC中的循环顺序需要颠倒。你还有一层额外的括号</p>
<pre><code>fourNest = [[[[[AA, BB, CC, DD]
for DD in range(5)]
for CC in range(4)]
for BB in range(3)]
for AA in range(2)]
</code></pre>