CherryPy Web 表单：复选框在未选中时产生错误

Question

我正在尝试使用 Python 3.5 中的 CherryPy（与 sqlite3 数据库进行比较）生成一个简单的 Web 表单，该表单需要输入一些不同类型的数据。当复选框未被选中时，它会产生错误，因为（我假设）没有默认的空值；它要么 'on' 要么不存在。如何更改我的表单，以便它自动将空框设置为 'None'？这是代码（部分）：

class startScreen(object):
    @cherrypy.expose
    def index(self):
        return """<form method="post" action="search">
        Job Title:<br>
        <input type="text" name="title"><br>
        Employer name:<br>
        <input type="text" name="employer"><br>
        Minimum Starting Salary:<br>
        <input type="number" name="minsal"><br>
        Contract Hours Per Week:<br>
        <input type="number" name="hpwMin">
        <input type="number" name="hpwMax"><br>
        Start Date:<br>
        <input type="date" name="startDate"><br>
        <!--jobtype drop down menu--!>
        Contract Length (months):<br>
        <input type="number" name="CLMin">
        <input type="number" name="CLMax"><br>
        <!--qualifications list--!>
        <!--key skills list--!>
        Training Offered:<br>
        <input type="checkbox" name="training"><br>
        Expenses covered:<br>
        <input type="checkbox" name="expenses"><br>
        Job benefits:<br>
        <input type="checkbox" name="benefits"><br>
        Number of days annual holiday: <br>
        <input type="number" name="holiday"><br>
        Opportunities abroad:<br>
        <input type="checkbox" name="abroad"><br>
        Date posted: <br>
        <input type="date" name="datePosted"><br>


        <button type="submit">Submit</button>
        </form>

        """
    @cherrypy.expose #needed for every page
    def search(self, title, employer, minsal, hpwMin, hpwMax, startDate, CLMin, CLMax, training, expenses, benefits, holiday, abroad, datePosted):
        search.search.searchDBS(title, employer, minsal, hpwMin, hpwMax, startDate, CLMin, CLMax, training, expenses, benefits, holiday, abroad, datePosted)
        return "done"

这是取消选中一个复选框时网页上的输出：

404 Not Found

Missing parameters: training

Traceback (most recent call last):
  File "C:\Users\Anna\AppData\Local\Programs\Python\Python35\lib\site-packages\cherrypy\_cpdispatch.py", line 60, in __call__
    return self.callable(*self.args, **self.kwargs)
TypeError: search() missing 1 required positional argument: 'training'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "C:\Users\Anna\AppData\Local\Programs\Python\Python35\lib\site-packages\cherrypy\_cprequest.py", line 670, in respond
    response.body = self.handler()
  File "C:\Users\Anna\AppData\Local\Programs\Python\Python35\lib\site-packages\cherrypy\lib\encoding.py", line 221, in __call__
    self.body = self.oldhandler(*args, **kwargs)
  File "C:\Users\Anna\AppData\Local\Programs\Python\Python35\lib\site-packages\cherrypy\_cpdispatch.py", line 66, in __call__
    raise sys.exc_info()[1]
  File "C:\Users\Anna\AppData\Local\Programs\Python\Python35\lib\site-packages\cherrypy\_cpdispatch.py", line 64, in __call__
    test_callable_spec(self.callable, self.args, self.kwargs)
  File "C:\Users\Anna\AppData\Local\Programs\Python\Python35\lib\site-packages\cherrypy\_cpdispatch.py", line 163, in test_callable_spec
    raise cherrypy.HTTPError(404, message=message)
cherrypy._cperror.HTTPError: (404, 'Missing parameters: training')

Answer 1

这是 html 复选框的常规行为，您可以使用默认参数处理它：training=None 或使用 kwargs 并查找键。

对于第一个选项，您的公开方法是：

@cherrypy.expose #needed for every page
def search(self, title, employer, minsal, hpwMin, hpwMax,
           startDate,  CLMin, CLMax, expenses,
           benefits, holiday, abroad, datePosted, training=None):
    # "training" will be None, if the checkbox is not set
    # you can verify with something like:
    # if training is None:
    #    ...
    search.search.searchDBS(
       title, employer, minsal, hpwMin, hpwMax,
       startDate, CLMin, CLMax, training, expenses,
       benefits, holiday, abroad, datePosted)
    return "done"

另一种选择（从我的角度来看更好，因为一个方法有很多参数，您可以使用 **params 替代方法：

@cherrypy.expose #needed for every page
def search(self, **params):
    fields = ['title', 'employer', 'minsal', 'hpwMin',
              'hpwMax', 'startDate', 'CLMin', 'CLMax',
              'training', 'expenses','benefits', 'holiday',
              'abroad','datePosted']
    # the params.get, will try to get the value if the field
    # and if is not defined, then it will return None
    search.search.searchDBS(*[params.get(f, None) for f in fields])
    # alternative approach without passing specific fields
    #if 'training' not in params: 
    #    params['training'] = None
    #search.search.searchDBS(**params)
    return "done"

CherryPy Web 表单：复选框在未选中时产生错误

CherryPy web form: checkboxes produces error when unchecked

html

python

sqlite

null

cherrypy