generator-expression

I just read the question Why is there no tuple comprehension in Python? In the comments of the accepted answer , it is stated that there are no true "tuple comprehensions". Instead, our current option is to use a generator expression and pass the resulting generator object to the tuple constructor: tuple(thing for thing in things) Alternatively, we can create a list using a list comprehension and then pass the list to the tuple constructor: tuple([thing for thing in things]) Lastly and to the contrary of the accepted answer, a more recent answer stated that tuple comprehensions are indeed a

I have came across this problem a few times and can't seem to figure out a simple solution. Say I have a string string = "a=0 b=1 c=3" I want to convert that into a dictionary with a, b and c being the key and 0, 1, and 3 being their respective values (converted to int). Obviously I can do this: list = string.split() dic = {} for entry in list: key, val = entry.split('=') dic[key] = int(val) But I don't really like that for loop, It seems so simple that you should be able to convert it to some sort of list comprehension expression. And that works for slightly simpler cases where the val can be

There are, as far as I know, three ways to create a generator through a comprehension 1 . The classical one: def f1(): g = (i for i in range(10)) The yield variant: def f2(): g = [(yield i) for i in range(10)] The yield from variant (that raises a SyntaxError except inside of a function): def f3(): g = [(yield from range(10))] The three variants lead to different bytecode, which is not really surprising. It would seem logical that the first one is the best, since it's a dedicated, straightforward syntax to create a generator through comprehension. However, it is not the one that produces the

I'm using Python 3.3.1 64-bit on Windows and this code snippet: len ([None for n in range (1, 1000000) if n%3 == 1]) executes in 136ms, compared to this one: sum (1 for n in range (1, 1000000) if n%3 == 1) which executes in 146ms. Shouldn't a generator expression be faster or the same speed as the list comprehension in this case? I quote from Guido van Rossum From List Comprehensions to Generator Expressions : ...both list comprehensions and generator expressions in Python 3 are actually faster than they were in Python 2! (And there is no longer a speed difference between the two.) EDIT: I