我恰好需要有加权平均价的计算, 每个型号有自己的加权平均价, 比如型号A, 就是把采购A的每一行的 数量* 单价=金额, 采购A 的所有的金额求和 再除 数量的和, 就得到加权平均价, 比如A的加权平均价= (5*10+5*15+2*16 ) / (5+5+2)=13.08
回答于 2021-09-23 22:21
变量值: >>> name = 'Eric' 输出时: >>> print('Hello %s, would you like to learn some Python today?' %name) Hello Eric, would you like to learn some Python today? 或者 >>> print('Hello {}, would you like to learn some Python today?'.format(name)) Hello Eric, would you lik...
回答于 2021-09-11 21:30
还是不行。AttributeError: module 'pygame' has no attribute 'MOUSEMOTIONDIR'。
回答于 2021-09-11 17:24
0.0000 0.0345 0.0345 0.0345 0.0000 0.0000 0.0000 0.0105 0.0345 0.0345 0.0345 0.0000 0.0000 0.0000 0.0209 -0.0107 -0.0107 -0.0107 0.0000 0.0000 0.0000 0.0314 0.0060 0.0060 0.0060 0.0000 0.0000 0.0000 0.0419 0.000...
回答于 2021-08-07 19:23
def open_spider(self, spider, start_requests=None, close_if_idle=True): print 'engine.open_spider open_spider()' assert self.has_capacity(), "No free spider slots when opening %r" % \ spider.name log.msg("Spider opened", spider=spider) nextcall = CallLaterOn...
回答于 2021-03-06 22:32
except是,发生错误时执行,而不是else时执行。if判断没发生错误,所以不会执行except里面的句子。 excep ... 明白了,非常感谢!
回答于 2021-02-28 12:18