range

Is there an unbounded version of range (or xrange for Python 2), or is it necessary to define it manually? For example squares = (x*x for x in range(n)) can only give me a generator for the squares up to (n-1)**2 , and I can't see any obvious way to call range(infinity) so that it just keeps on truckin'. You're describing the basic use of itertools.count : import itertools squares = (x*x for x in itertools.count()) 来源： https://stackoverflow.com/questions/7186336/unbounded-range

Is there something existing in python that can convert an increasing list of integers into a range list E.g. given the set {0, 1, 2, 3, 4, 7, 8, 9, 11} I want to get { {0,4}, {7,9}, {11,11} }. I can write a program to do this, but want to know if there is an inbuilt function in python Using itertools.groupby() produces a concise but tricky implementation: import itertools def ranges(i): for a, b in itertools.groupby(enumerate(i), lambda (x, y): y - x): b = list(b) yield b[0][1], b[-1][1] print list(ranges([0, 1, 2, 3, 4, 7, 8, 9, 11])) Output: [(0, 4), (7, 9), (11, 11)] You can use a list

I'm trying to create a chart with a range built dynamically using the INDIRECT function. Excel does recognize the range I am creating using INDIRECT as it highlights the corresponding range on the sheet: However when saving the chart, I get an error message saying the function is not valid: Does anybody know what the problem is / how to create a dynamic chart range from a specific start to specific end point? PS: You can download the above spreadsheet here . The formula I was using: =INDIRECT("sheet!"&E2&":"&E3) Mine is similar to Sean's excellent answer, but allows a start and end day. First

Is there a way to test a range without doing this redundant code: if ($int>$min && $int<$max) ? Like a function: function testRange($int,$min,$max){ return ($min<$int && $int<$max); } usage: if (testRange($int,$min,$max)) ? Does PHP have such built-in function? Or any other way to do it? I don't think you'll get a better way than your function. It is clean, easy to follow and understand, and returns the result of the condition (no return (...) ? true : false mess). Tested your 3 ways with a 1000000-times-loop. t1_test1: ($val >= $min && $val <= $max) : 0.3823 ms t2_test2: (in_array($val, range

This question already has an answer here: Loop backwards using indices in Python? 14 answers I'm talking about doing something like: for(i=n; i>=1; --i) { //do something with i } I can think of some ways to do so in python (creating a list of range(1,n+1) and reverse it, using while and --i , ...) but I wondered if there's a more elegant way to do it. Is there? EDIT: Some suggested I use xrange() instead of range() since range returns a list while xrange returns an iterator. But in Python 3 (which I happen to use) range() returns an iterator and xrange doesn't exist. Chinmay Kanchi range() and

I am getting an error when running a python program: Traceback (most recent call last): File "C:\Program Files (x86)\Wing IDE 101 4.1\src\debug\tserver\_sandbox.py", line 110, in <module> File "C:\Program Files (x86)\Wing IDE 101 4.1\src\debug\tserver\_sandbox.py", line 27, in __init__ File "C:\Program Files (x86)\Wing IDE 101 4.1\src\debug\tserver\class\inventory.py", line 17, in __init__ builtins.NameError: global name 'xrange' is not defined The game is from here . What causes this error? You are trying to run a Python 2 codebase with Python 3. xrange() was renamed to range() in Python 3.