tuples

If we define __str__ method in a class: class Point(): def __init__(self, x, y): self.x = x self.y = y def __str__(self, key): return '{},{}'.format(self.x, self.y) So we can convert its object to str immediately: a = Point(1, 1) b = str(a) print(b) But as far as I know, there is not such __tuple__ magic method, so I do not know how to define a class which can pass to tuple() so that we can convert its object to tuple immediately. The tuple "function" (it's really a type, but that means you can call it like a function) will take any iterable, including an iterator, as its argument. So if you

I have a list of nested tuples of the form: [(a, (b, c)), ...] Now I would like to pick the element which maximizes a while minimizing b and c at the same time. For example in [(7, (5, 1)), (7, (4, 1)), (6, (3, 1))] the winner should be (7, (4, 1)) Any help is appreciated. In my understanding, you want to sort decreasingly by a, and ascendingly by b, then by c. If that's right, you can do it like so: >>> l=[(7, (5, 1)), (7, (4, 1)), (6, (3, 2)), (6, (3, 1))] >>> sorted(l, key = lambda x: (-x[0], x[1])) [(7, (4, 1)), (7, (5, 1)), (6, (3, 1)), (6, (3, 2))] Picking the "winner" would be as simple

I'm trying to get my head around Swift (after being relatively competent with Obj-C) by making a small app. I would like to use NSUserDefaults to persistently save a small amount of data but I am having problems. I initialise an empty array of tuples like this: var costCategoryArray: [(name:String, defaultValue:Int, thisMonthsEstimate:Int, sumOfThisMonthsActuals:Int, riskFactor:Float, monthlyAverage:Float)]=[] When the array has an entry, I want to save the array to NSUserDefaults with standard Swift code such as this: NSUserDefaults.standardUserDefaults().setObject(costCategoryArray, forKey:

old = [('ver','1121'),('sign','89'),('address','A45'),('type','00')] new = [('ver','1121'),('sign','89'),('type','01')] I need to compare the new list against old one based on first element of the tuples, and show the difference between whatever elements new list has, so that the output should look like: Match : ver = 1121 Match : sign = 89 Mismatch : type = 01 (old : 00) I could get all the matching tuples with below list comprehension but could not think beyond it. my_list = [(a,b) for (a,b) in new for (c,d) in old if ((a==c) and (b==d))] print( my_list) Please suggest me a way to do it.

This question already has an answer here: When are parentheses required around a tuple? 3 answers So I stumbled into a particular behaviour of tuples in python that I was wondering if there is a particular reason for it happening. While we are perfectly capable of assigning a tuple to a variable without explicitely enclosing it in parentheses: >>> foo_bar_tuple = "foo","bar" >>> we are not able to print or check in a conditional if statement the variable containing the tuple in the previous fashion (without explicitely typing the parentheses): >>> print foo_bar_tuple == "foo","bar" False bar >