我从这段代码中得到了异常:
class Transaction:
def __init__ (self):
self.materials = {}
def add_material (self, m):
self.materials[m.type + m.purity] = m
def serialize (self):
ser_str = 'transaction_start\n'
for k, m in self.materials:
ser_str += m.serialize ()
sert += 'transaction_end\n'
return ser_str
抛出异常的是for
行。m
是Material
对象。有人知道为什么吗?
发布于 2011-08-14 06:02:27
for k, m in self.materials.items():
示例:
miles_dict = {'Monday':1, 'Tuesday':2.3, 'Wednesday':3.5, 'Thursday':0.9}
for k, v in miles_dict.items():
print("%s: %s" % (k, v))
https://stackoverflow.com/questions/7053551
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