Re: dict.updated

[hanz]

Rick Morrison wrote:
> >>> [updated(d, {'c':3}) for d in [{'a':1, 'b':2}, {'x':10,
'y':'11'}]]
> [{'a': 1, 'c': 3, 'b': 2}, {'y': '11', 'x': 10, 'c': 3}]

I don't really understand the use of this. Can you give a less toy
example? I'd probably just do

dicts = [{'a':1, 'b':2}, {'x':10, 'y':'11'}]
for d in dicts: d.update({'c':3})

This isn't really more typing or any clumsier IMO, so I can't see why
you'd want to use list comprehensions in this case.

-- 
http://mail.python.org/mailman/listinfo/python-list

Re: lambda

[hanz]

Antoon Pardon wrote:
> So if I have a call with an expression that takes more than
> one line, I should assign the expression to a variable and
> use the variable in the call?

Yes, that's sometimes a good practice and can clarify
the call.

> But wait if I do that, people will tell me how bad that it
> is, because it will keep a reference to the value which
> will prevent the garbage collector from harvesting this
> memory.

Nobody will tell you that it's bad. Python was never
about super performance, but about readability.
Besides, using such temporaries won't consume much
memory (relatively).

> Besides python allows more than one statement on the same line.
But it's discouraged in general.

-- 
http://mail.python.org/mailman/listinfo/python-list

Re: dynamically inserting function into an object

[hanz]

# class Cell(object):
# def __init__(self, initialvalue = 0):
#self._func = lambda x: x
#self.__value = initialvalue
#
# def setvalue (self, newvalue):
# self.__value = self._func(newvalue)
#
# def getvalue (self):
# return self.__value
#
# def delvalue (self):
# del self.__value
#
# value = property(getvalue, setvalue, delvalue, "I'm the 'value'
property.")
#
# def curry(self, func, *args):
# self._func = lambda x: func(x, *args)

-- 
http://mail.python.org/mailman/listinfo/python-list