如何在python-eve應用程序中返回更有意義的500錯誤

Question

我在python-eve應用程序中有一些代碼，它從設備檢索一些數據，並在第一次請求該資源時填充資源。 有時代碼無法成功連接到設備。 在這種情況下，我想返回一條更好地解釋這一點的錯誤消息，而不僅僅是一個普通的500錯誤。 這是on_fetch_item鈎子：

def before_returning_item(resource, _id, document):
if resource == "switches":
    if "interfaces" not in document.keys():
        # retrieve and store switch config if it hasn't been stored yet
        r = app.data.driver.db[resource]
        try:
            switch = prepare_switch_from_document(document)
        except socket.timeout:
            # raise some more meaningful error with message
            pass
        interface_list = switch.get_formatted_interfaces()
        r.update({'_id': _id}, {'interfaces': interface_list})
        document['interfaces'] = interface_list

app.on_fetch_item += before_returning_item

提前致謝。

Answer 1

您所要做的就是利用Flask的abort方法：

from flask import abort

def before_returning_item(resource, _id, document):
    if resource == "switches":
        if "interfaces" not in document.keys():
            # retrieve and store switch config if it hasn't been stored yet
            r = app.data.driver.db[resource]
            try:
                switch = prepare_switch_from_document(document)
            except socket.timeout:
                # raise some more meaningful error with message
                abort(500)
            interface_list = switch.get_formatted_interfaces()
            r.update({'_id': _id}, {'interfaces': interface_list})
            document['interfaces'] = interface_list

    app.on_fetch_item += before_returning_item

如果要添加自定義說明：

abort(500, description='My custom abort description')

Answer 2

我喜歡創建自定義異常，並提出具有意義注釋的異常，例如：

class MyExcept(Exception): pass

def before_returning_item():
    ...
    if error_condition:
        raise MyException('detailed explanation')
    ...

try:
    before_returning_item()
except MyException, exc:
    if 'device not ready' in str(exc):
        print("Device was not rdy...Try agin?")
    else:
        raise