关于float，赋值

阿萨姆奶茶一箱15支装。

在http://www.ds365.com/                      的价格是44

在http://www.synergyiclub.com:8086/          的价格是45

外面零售是4.5一支

在计算对比是，44/15 的结果变成了2，实际应该是2.9333333

WHY？

代码：

-----------------------------------

box_ds = 44

box_syn = 45

num_in_box = 15

per_sale_retail_price = 4

print "Here is the incorrect method:"

per_ds_incorrect = box_ds / num_in_box #Why did it calculate incorrectly here?

print "See what will happen now:"

per_ds = float(box_ds) / float(num_in_box)

per_syn = box_syn / num_in_box

print per_ds

print per_ds_incorrect

print "The num what I want is %f" % per_ds

print "The num what I don't want is %r " % per_ds_incorrect

print "The price of a bottle Asamu Milktea  on ds is : %r" % per_ds

print "The price of a bottle Asamu Milktea on Synergy is : %s" % per_syn

print "The price of a bottle Asamu Milktea on retail is : %r" % per_sale_retail_price

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总结：必须使用浮点型，但是以下是错的：

float(per_ds_incorrect = box_ds / num_in_box)

float(per_ds_incorrect）= box_ds / num_in_box

per_ds_incorrect）= float(box_ds / num_in_box

正确的是：

per_ds = float(box_ds) / float(num_in_box)

本文出自 “StudyLog” 博客，谢绝转载！