擅长:python、mysql、java
<p>每次生成一个随机数。由于循环的内部工作只关心单个随机数,因此在循环内生成并使用它。</p>
<p>示例:</p>
<pre><code># do this:
import random
for x in xrange(SOMEVERYLARGENUMBER):
n = random.randint(1,1000) # whatever your range of random numbers is
# Do stuff with n
# don't do this:
import random
# This list comprehension generates random numbers in a list
numbers = [random.randint(1,1000) for x in xrange(SOMEVERYLARGENUMBER)]
for n in numbers:
# Do stuff with n
</code></pre>
<p>显然,实际上这并不重要,除非你要处理数十亿次的迭代,但是如果你一次只使用一个,为什么还要费心生成所有这些数字呢?</p>