尝试...除外...除外...:如何避免重复代码
问题描述:
- 我想避免在多个地方写入
errorCount + = 1
。 - 我正在寻找比
success = False
try:
...
else:
success = True
finally:
if success:
storage.store.commit()
else:
storage.store.rollback()
- 我正在尝试避免
store.rollback()
在每个except子句中。 - I'm trying to avoid
store.rollback()
in every except clause.
关于如何执行此操作的任何想法?
Any idea on how to do this?
count = 0
successCount = 0
errorCount = 0
for row in rows:
success = False
count += 1
newOrder = storage.RepeatedOrder()
storage.store.add(newOrder)
try:
try:
newOrder.customer = customers[row.customer_id]
except KeyError:
raise CustomerNotFoundError, (row.customer_id,)
newOrder.nextDate = dates[row.weekday]
_fillOrder(newOrder, row.id)
except CustomerNotFoundError as e:
errorCount += 1
print u"Error: Customer not found. order_id: {0}, customer_id: {1}".format(row.id, e.id)
except ProductNotFoundError as e:
errorCount += 1
print u"Error: Product not found. order_id: {0}, product_id: {1}".format(row.id, e.id)
else:
success = True
successCount += 1
finally:
if success:
storage.store.commit()
else:
storage.store.rollback()
print u"{0} of {1} repeated orders imported. {2} error(s).".format(successCount, count, errorCount)
答
这看起来像是Python的新 with
语句的可能应用程序,它允许撤消操作并安全释放资源,无论结果是什么代码块
This look like a possible application of Python's new with
statement. It allows to to unwind operations and release resources securely no matter what outcome a block of code had.
在 PEP 343