每次生成一个随机数。由于循环的内部工作原理只关心单个随机数,因此请在循环内部生成并使用它。
例:
# 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
显然,从实际意义上讲,这并不重要,除非您要处理数十亿次迭代,但是如果您一次只使用一个,为什么还要麻烦生成所有这些数字呢?