产生一个递增的list：
num_inc_list = range(30)
#will return a list [0,1,2,...,29]产生一个固定初始值的list：
initial_value = 0
list_length = 5
sample_list = [ initial_value for i in range(10)]
sample_list = [initial_value]*list_length
# sample_list ==[0,0,0,0,0]原文地址：http://blog.csdn.net/puqutogether/article/details/44900375
