将多个try/except块转换为函数

Question

这是一个更一般的编程问题，而不是与实际代码相关的问题

我有一个难看的代码，它从JIRA获取一个输入，并将其从毫秒转换为小时，多次写出，如下所示：

def convertMillis(ms):
    hours = ms / 1000 / 60 / 60
    return hours

try:
    newaccsla_comp = convertMillis(issues.fields.customfield_10705.completedCycles[0].remainingTime.millis)
except:
    newaccsla_comp = np.nan
try:
    newaccsla_ongoing = convertMillis(issues.fields.customfield_10705.ongoingCycle.remainingTime.millis)
except:
    newaccsla_ongoing = np.nan

try:
    paymentssla_comp = convertMillis(issues.fields.customfield_10136.completedCycles[0].remainingTime.millis)
except:
    paymentssla_comp = np.nan
try:
    paymentssla_ongoing = convertMillis(issues.fields.customfield_10136.ongoingCycle.remainingTime.millis)
except:
    paymentssla_ongoing = np.nan

try:
    modifysla_comp = convertMillis(issues.fields.customfield_10713.completedCycles[0].remainingTime.millis)
except:
    modifysla_comp = np.nan
try:
    modifysla_ongoing = convertMillis(issues.fields.customfield_10713.ongoingCycle.remainingTime.millis)
except:
    modifysla_ongoing = np.nan

try:
    MFsla_comp = convertMillis(issues.fields.customfield_10711.completedCycles[0].remainingTime.millis)
except:
    MFsla_comp = np.nan
try:
    MFsla_ongoing = convertMillis(issues.fields.customfield_10711.ongoingCycle.remainingTime.millis)
except:
    MFsla_ongoing = np.nan

try:
    closeaccsla_comp = convertMillis(issues.fields.customfield_10140.completedCycles[0].remainingTime.millis)
except:
    closeaccsla_comp = np.nan
try:
    closeaccsla_ongoing = convertMillis(issues.fields.customfield_10140.ongoingCycle.remainingTime.millis)
except:
    closeaccsla_ongoing = np.nan

try:
    casla_comp = convertMillis(issues.fields.customfield_10213.completedCycles[0].remainingTime.millis)
except:
    casla_comp = np.nan
try:
    casla_ongoing = convertMillis(issues.fields.customfield_10213.ongoingCycle.remainingTime.millis)
except:
    casla_ongoing = np.nan

try:
    at_comp = convertMillis(issues.fields.customfield_10144.completedCycles[0].remainingTime.millis)
except:
    at_comp = np.nan
try:
    at_ongoing = convertMillis(issues.fields.customfield_10144.ongoingCycle.remainingTime.millis)
except:
    at_ongoing = np.nan

try:
    modfeesla_comp = convertMillis(issues.fields.customfield_10134.completedCycles[0].remainingTime.millis)
except:
    modfeesla_comp = np.nan
try:
    modfeesla_ongoing = convertMillis(issues.fields.customfield_10134.ongoingCycle.remainingTime.millis)
except:
    modfeesla_ongoing = np.nan

try:
    tdsla_comp = convertMillis(issues.fields.customfield_11200.completedCycles[0].remainingTime.millis)
except:
    tdsla_comp = np.nan
try:
    tdsla_ongoing = convertMillis(issues.fields.customfield_11200.ongoingCycle.remainingTime.millis)
except:
    tdsla_ongoing = np.nan

try:
    querysla_comp = convertMillis(issues.fields.customfield_10142.completedCycles[0].remainingTime.millis)
except:
    querysla_comp = np.nan
try:
    querysla_ongoing = convertMillis(issues.fields.customfield_10142.ongoingCycle.remainingTime.millis)
except:
    querysla_ongoing = np.nan

try:
    recsla_comp = convertMillis(issues.fields.customfield_15600.completedCycles[0].remainingTime.millis)
except:
    recsla_comp = np.nan
try:
    recsla_ongoing = convertMillis(issues.fields.customfield_15600.ongoingCycle.remainingTime.millis)
except:
    recsla_ongoing = np.nan

try:
    reportsla_comp = convertMillis(issues.fields.customfield_15601.completedCycles[0].remainingTime.millis)
except:
    reportsla_comp = np.nan
try:
    reportsla_ongoing = convertMillis(issues.fields.customfield_15601.ongoingCycle.remainingTime.millis)
except:
    reportsla_ongoing = np.nan

我很乐意做一些事情，比如获取所有自定义字段，将它们放在一个列表中，然后对函数执行for操作，如下所示：

field_list = ['customfield_10705','customfield_10136','customfield_10713','customfield_10711','customfield_10140','customfield_10213','customfield_10144','customfield_10134','customfield_11200','customfield_10142','customfield_15600','customfield_15601']


  def get_jira_hours(field):
        try:
            newaccsla_comp = convertMillis(issues.fields.field.completedCycles[0].remainingTime.millis)
        except:
            newaccsla_comp = np.nan
        try:
            newaccsla_ongoing = convertMillis(issues.fields.field.ongoingCycle.remainingTime.millis)
        except:
            newaccsla_ongoing = np.nan

for field in field_list:
    get_jira_hours(field)

但是，有三个变量链接到我需要迭代的每个函数调用—保存每个try/的customfield_10705和名称newaccsla_comp和newaccsla_ongoing

变量按顺序排列。。即field_list[0]链接到name_list[0]

field_list = ['customfield_10705','customfield_10136','customfield_10713','customfield_10711','customfield_10140','customfield_10213','customfield_10144','customfield_10134','customfield_11200','customfield_10142','customfield_15600','customfield_15601']

name_list = ['newaccsla','paymentssla','modifysla','MFsla','closeaccsla','casla','at','modfeesla','tdsla','querysla','recsla','reportssla']

迭代这些的最佳方法是什么？谢谢

Answer 1

首先，如果您只需编辑convertMillis函数以返回np.nan而不是提升函数，则可以将这四个行块中的每一个都转换为一个行，或者，如果您不能这样做，则可以将函数包装为另一个行：

def convertMillisOrNan(millis):
    try:
        return convertMillis(millis)
    except:
        return np.nan

newaccsla_comp = convertMillisOrNan(issues.fields.customfield_10705.completedCycles[0].remainingTime.millis)
newaccsla_ongoing = convertMillisOrNan(issues.fields.customfield_10705.ongoingCycle.remainingTime.millis)
# etc.

---

或者，也许你试图处理的异常会更进一步。你总是在<something>.remainingTime.millis上给convertMillis打电话。如果字段总是存在，并且总是有一个ongoingCycle，但是它并不总是有remainingTime属性呢？然后您可以将该部分推入try:，同时还可以进一步简化：

def convertCycle(cycle):
    try:
        return convertMillis(cycle.remainingTime.millis)
    except:
        return np.nan
newaccsla_comp = convertCycle(issues.fields.customfield_10705.completedCycles[0])
newaccsla_ongoing = convertCycle(issues.fields.customfield_10705.ongoingCycle)

---

如果异常出现得更高—例如，如果字段不总是有ongoingCycle—显然您需要在try:块内推送更多的表达式；我真的只是想猜测一下你想处理什么

---

而且，当你这么做的时候，你真的想要一个光秃秃的except:？它将处理任何异常，而不仅仅是AttributeError或ValueError或您实际期望的任何类型的异常

---

同时，现有的jira_hours重构无法工作，因为当field是一个包含字符串的变量时，不能只使用.field。解决这个问题的方法之一是：

def get_jira_hours(field):
    comp = convertCycle(field.completedCycles[0])
    ongoing = convertCycle(field.ongoingCycle)
    return comp, ongoing

newaccsla_comp, newaccsla_ongoing = get_jira_hours(issues.fields.customfield_10705)
paymentssla_comp, paymentssla_ongoing = get_jira_hours(issues.fields.customfield_10136)
# etc.

另一种解决方法是使用getattr——我将在下面展示

---

但你可以做得更好。你真的需要这些都是自变量，而不是，比方说，dict中的条目吗

fieldmap = {
    'newaccsla': 'customfield_10136',
    'paymentssla': 'customfield_10705',
    # etc.
}

values = {}
for fieldname, customfieldname in fieldmap.items():
    field = getattr(issues.fields, customfieldname)
    comp, ongoing = get_jira_hours(field)
    values[f'{fieldname}_comp'] = comp
    values[f'{fieldname}_ongoing'] = ongoing

现在，您必须使用values['newaccsla_comp']，而不是使用newaccsla_comp。但是我怀疑你的代码实际上会做很多代码，你会为每个变量复制和粘贴相同的东西，你可以用在dict上循环的代码来代替

但是如果你真的需要这些变量作为自变量，你也可以用globals()或者locals()来代替values

另一方面，如果您要在comp/正在进行的值对上重复自己，只需将这些值对存储在dict:values[fieldname] = comp, ongoing

另外，由于所有自定义字段名似乎都是customfield_NNNNN，您可以通过映射'newaccsla': 10136等，然后执行getattr(issue.fields, f'customfield_{customfield}')，进一步简化操作