iteration

问题 Here is the combination / permutator generator function that uses any number of lists with values and any length of template strings. The generator creates corresponding lists with combinations / permutations of values matching the template string. The answer was given by a colleague here: https://stackoverflow.com/a/48121777/8820330 from itertools import permutations, combinations, product def groups(sources, template, mode='P'): func = permutations if mode == 'P' else combinations keys =

问题 I'm getting this error only when the field is defined in a form that contains other fields- but when its defined in a it's own form, this error is not generated and it works. Firstly I will show what works successfully: class TrackForm(Form): name = StringField('Name') start = StringField('Start') end = StringField('End') class Merge(Form): item_description = FieldList(FormField(TrackForm), min_entries=1, max_entries=32) view.py @app.route('/test', methods=['GET', 'POST']) def test(): form

问题 I've found different versions of heap sort for python, but I can't seem to find the one that matches my needs. Iterative Heap Sort is the closest I found, but I can't quite figure out how to change it to work with a sub-list (index start, index end) and remain in place. If I get it right then I'll post my answer here. If anyone has an implementation in even C or Java that will be great. 回答1: I managed to do what I want. This code works on objects and sorts by a specific attribute. def

问题 I have a folder with 10 files that I import in R as S S<-list.files(S1_path, recursive = TRUE, full.names = TRUE, pattern="S1") > S [1] "/shared/Training/EARSEL0918_UrbanClassification_Germany/Original//S1A_IW_SLC__1SDV_20180412T171648_20180412T171715_021437_024E95_BDA1.zip" [2] "/shared/Training/EARSEL0918_UrbanClassification_Germany/Original//S1A_IW_SLC__1SDV_20180424T171648_20180424T171715_021612_02540A_BB21.zip" [3] "/shared/Training/EARSEL0918_UrbanClassification_Germany/Original//S1A_IW

问题 I have a dataframe with 12 column. I would like to extract the rows of a column depending on the values of another column. Sample of my dataframe order_id order_type order_items 45 Lunch [('Burger', 5), ('Fries', 6)] 12 Dinner [('Shrimp', 10), ('Fish&Chips', 7)] 44 Lunch [('Salad', 9), ('Steak', 9)] 23 Breakfast [('Coffee', 2), ('Eggs', 3)] I would like to extract the breakfast, lunch and dinner menu by extracting the first item of each tuple . and extract the number of orders from the next

问题 For the following lines of code, once I enter my locationArray into the data, the iteration runs for the length of the array, but starts on the final iteration such that i is always = 1 (the array has a length of two nested arrays). Why won't it start with array[0]? var canvas = d3.select("#map-canvas"); setTimeout(function(){ console.log(canvas) canvas .selectAll(".marker") .append('svg') .attr('width', 400) .attr('height', 400) .style("position", "relative") .style("right", 150) .style(

问题 I have a tree structured model and designed it with composite Pattern. for iterating through the entire hierachy Im using Composite Iteration. I have used this tutorial: http://www.blackwasp.co.uk/Composite.aspx but when I want to AutoMap the model, I encounter this problem: {"The entity '<GetEnumerator>d__0' doesn't have an Id mapped. Use the Id method to map your identity property. For example: Id(x => x.Id)."} but getEnumerator is a method. I don't know why handle this like an Entity!!

问题 In Scala, while iterating through the elements of a LinkedList, I would like to have some method remove() which removes the current element and (very important) makes the iterator point to the next element (or to the first if the current element is the last one; to null or something if there are no more elements). 回答1: Not sure if this what you want but how about: @annotation.tailrec def round(xs: Set[(Int, Int)]) = { // here you might check if items are exhausted and possibly don't go

问题 I've looked at other solutions to this, such as: Mongodb: Connection reset by peer Mongodb : AutoReconnect, Connection reset by peer But still have this error. I'm trying to load a large GeoJSON file into MongoDB. Here's my code: https://gist.github.com/mittenchops/6499844 using the iterative json parser here: https://github.com/isagalaev/ijson Here is my error: Traceback (most recent call last): File "upload2mongo.py", line 57, in <module> main(sys.argv) File "upload2mongo.py", line 52, in

问题 I need to get the cartesian product of iterables, like itertools.product gives me, but for optimization reasons I want those pairs/combinations with the lowest sum of indices to appear first. So, for example, if I have two lists, a = [1, 2, 3, 4, 5] and b = ['a', 'b', 'c', 'd', 'e'] , itertools.product gives me: >>> list(itertools.product(a, b)) [(1, 'a'), (1, 'b'), (1, 'c'), (1, 'd'), (1, 'e'), (2, 'a'), (2, 'b'), (2, 'c'), (2, 'd'), (2, 'e'), (3, 'a'), (3, 'b'), (3, 'c'), (3, 'd'), (3, 'e')