<p>我在几个嵌套的循环中循环。如果第一个循环的项发生变化,我想打印它。我怎么能做到呢?在</p>
<pre><code>for slope in slopeList:
for yarddist in yardDistList:
for chiptreesperacre in chipAcreList:
for chipvolpertree in chipVolList:
for smalllognumber in smallAcreList:
for smalltreevolpertree in smallVolList:
for largelogperacre in largeAcreList:
for largetreevolpertree in largeVolList:
data = [slope, yarddist, chiptreesperacre, chipvolpertree, smalllognumber, smalltreevolpertree, largelogperacre, largetreevolpertree]
if slope changes:
print data
</code></pre>
<p>存储您以前看到的值,并将其进行比较:</p>
<pre><code>previous_slope = None
for slope in as_many_loops_as_you_like:
data = [slope, other_stuff]
if slope != previous_slope:
print data
previous_slope = slope
</code></pre>