iterable

问题 Say I have a list of tuples, like the following: listo = [('a','1'),('b','0'),('c','2'),('d','0')] If I want the lowest tuple, based on the second index of each tuple, I can customize the min function with a lambda function, like this: min(listo, key=lambda x: x[1]) As it stands, this code would return: In [31]: min(listo, key=lambda x: x[1]) Out[31]: ('b', '0') But this only gives me one tuple, and only the first one it encounters at that. What if I wanted ALL the min tuples? So it returns

来源： https://stackoverflow.com/questions/43935187/how-come-an-object-that-implements-iter-is-not-recognized-as-iterable

问题 I want to do a string list filter function using an Iterable<String> and a predicate to select the strings to keep, the other ones must be removed from the list, but I'm not understating how I do the remove. static <T> Iterable<T> select(Iterable<T> it, Predicate<T> pred) { for (T s: it) { if (pred.test(s)==false) { // what to do here? } } return ...; } For this input: {"a","","b",""} I expect {"a","b"} 回答1: An Iterable represents the capability to provide an Iterator on request. So, to

问题 I want to do a string list filter function using an Iterable<String> and a predicate to select the strings to keep, the other ones must be removed from the list, but I'm not understating how I do the remove. static <T> Iterable<T> select(Iterable<T> it, Predicate<T> pred) { for (T s: it) { if (pred.test(s)==false) { // what to do here? } } return ...; } For this input: {"a","","b",""} I expect {"a","b"} 回答1: An Iterable represents the capability to provide an Iterator on request. So, to

问题 I'm trying to find an elegant way to find the max value in a two-dimensional array. for example for this array: [0, 0, 1, 0, 0, 1] [0, 1, 0, 2, 0, 0][0, 0, 2, 0, 0, 1][0, 1, 0, 3, 0, 0][0, 0, 0, 0, 4, 0] I would like to extract the value '4'. I thought of doing a max within max but I'm struggling in executing it. 回答1: Max of max numbers ( map(max, numbers) yields 1, 2, 2, 3, 4): >>> numbers = [0, 0, 1, 0, 0, 1], [0, 1, 0, 2, 0, 0], [0, 0, 2, 0, 0, 1], [0, 1, 0, 3, 0, 0], [0, 0, 0, 0, 4, 0] >>

问题 I'm trying to find an elegant way to find the max value in a two-dimensional array. for example for this array: [0, 0, 1, 0, 0, 1] [0, 1, 0, 2, 0, 0][0, 0, 2, 0, 0, 1][0, 1, 0, 3, 0, 0][0, 0, 0, 0, 4, 0] I would like to extract the value '4'. I thought of doing a max within max but I'm struggling in executing it. 回答1: Max of max numbers ( map(max, numbers) yields 1, 2, 2, 3, 4): >>> numbers = [0, 0, 1, 0, 0, 1], [0, 1, 0, 2, 0, 0], [0, 0, 2, 0, 0, 1], [0, 1, 0, 3, 0, 0], [0, 0, 0, 0, 4, 0] >>

问题 I can do >>> s = {1} >>> type(s) <class 'set'> but >>> s = set(1) Traceback (most recent call last): File "<stdin>", line 1, in <module> TypeError: 'int' object is not iterable what is the difference? 回答1: The difference is that the set() constructor takes an iterable. A single number is not an iterable. s = set((1,)) 来源： https://stackoverflow.com/questions/27180659/build-a-set-fails-when-using-setint-python

问题 I can do >>> s = {1} >>> type(s) <class 'set'> but >>> s = set(1) Traceback (most recent call last): File "<stdin>", line 1, in <module> TypeError: 'int' object is not iterable what is the difference? 回答1: The difference is that the set() constructor takes an iterable. A single number is not an iterable. s = set((1,)) 来源： https://stackoverflow.com/questions/27180659/build-a-set-fails-when-using-setint-python

问题 I can do >>> s = {1} >>> type(s) <class 'set'> but >>> s = set(1) Traceback (most recent call last): File "<stdin>", line 1, in <module> TypeError: 'int' object is not iterable what is the difference? 回答1: The difference is that the set() constructor takes an iterable. A single number is not an iterable. s = set((1,)) 来源： https://stackoverflow.com/questions/27180659/build-a-set-fails-when-using-setint-python

问题 Is there a scenario where the container is not iterable, according to this graph? 回答1: Depends on what you mean by always . According to collections.abc a container is an object that implements __contains__ method an iterable is an object that implements __iter__ (or __getitem__ , as a fallback) So, theoretically, no, you can implement a container that is not an iterable. However, all standard python containers (and most containers implemented by libraries) are also iterable. 来源： https:/