Databases
StackOverflow2013
Postsdbo
PO
 

Note that there are some explanatory texts on larger screens.

plurals
  1. PO
    primarykey
    data
    text
    <p>This works, and is less gross after several improvements (props to @jchl), but still seems like it should be unecessary, especially considering that you get this for free with "old-style" classes. </p> <p>I'm still looking for a better answer. If there's no better method, this seems to me like a regression in the Python language.</p> <pre><code>def ops_list(): "calculate the list of overloadable operators" #&lt;type 'object'&gt; has functions but no operations not_ops = dir(object) #calculate the list of operation names ops = set() for mytype in (int, float, str): for op in dir(mytype): if op.endswith("__") and op not in not_ops: ops.add(op) return sorted(ops) class MetaCastable(type): __ops = ops_list() def __new__(mcs, name, bases, dict): #pass any undefined ops to self.__op__ def add_op(op): if op in dict: return fn = lambda self, *args: self.__op__(op, args) fn.__name__ = op dict[op] = fn for op in mcs.__ops: add_op( op ) return type.__new__(mcs, name, bases, dict) class Castable(object): __metaclass__ = MetaCastable def __str__(self): print "str!" return "&lt;Castable&gt;" def __int__(self): print "int!" return 42 def __float__(self): print "float!" return 2.718281828459045 def __op__(self, op, args): try: other = args[0] except IndexError: other = None print "%s %s %s" % (self, op, other) self, other = coerce(self, other) return getattr(self, op)(*args) def __coerce__(self, other): print "coercing like %r!" % other if other is None: other = 0.0 return (type(other)(self), other) </code></pre>
    singulars
    1. This table or related slice is empty.
    1. POPython: coerce new-style class
      singulars
      1. PTQuestion
    1. PTAnswer
    1. USbukzor
    1. USbukzor
    plurals
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. POPython: coerce new-style class
      singulars
      1. PTQuestion
    1. This table or related slice is empty.
    1. VO
      singulars
      1. PO
      1. This table or related slice is empty.
      1. VTUpMod
    2. VO
      singulars
      1. PO
      1. This table or related slice is empty.
      1. VTUpMod
    3. VO
      singulars
      1. PO
      1. This table or related slice is empty.
      1. VTUpMod
    1. COI actually think this is a pretty neat solution. Given that Python doesn't seem to provide this functionality, this is not many lines of code to add a pretty powerful feature to the language.
      singulars
      1. PO
      1. USjchl
    2. COThere are a few things you could do to make it neater still. Better to modify `dict` before calling `type.__new__` than to use `setattr` afterwards. Better to give your lambda functions an appropriate `__name__`, and to use a closure rather than the default arguments trick, so that they have the proper prototype. And I'm not sure whether you consider it a feature that it assumes that the type doesn't define `__radd__` if it doesn't define `__add__`, or whether this is a bug.
      singulars
      1. PO
      1. USjchl
    3. CO@jchl: thanks. I'll do those after work, or you can feel free and try to grab the bounty. I guess the main thing I hate about this solution is the static lists _unary and _binary. It also doesn't support the 3-argument pow() operator.
      singulars
      1. PO
      1. USbukzor
 

Querying!

 
Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload