tuples

I'm trying to make a call to a templated function like this : typedef std::tuple<int, double, bool> InstrumentTuple; Cache cache; InstrumentTuple tuple = cache.get<InstrumentTuple>(); I know I could "simply" pass the types of the tuple. This is what I do know but it is quite cumbersome since I make a lot of calls to this function and since the tuples are quite long: InstrumentTuple tuple = c.get<int, double, bool>(); // syntax I'd like to avoid So I tried multiple implementations of the get method, but with no success : Enabling via a template parameter #include <tuple> class Cache { private:

I started using the new tuple feature in c# 7.0 but I noticed that neither in the function that returns a tuple nor in its caller is possible to check the variable values in debug mode. Instead an exception is shown: $exception error CS8182: Predefined type 'ValueTuple`2' must be a struct. Is there a way to get rid of that glitch and debug normally? It seems a bug that Microsoft has fixed but it will be available in a future update (2017) https://github.com/dotnet/roslyn/pull/16930 It is a bug in the current version of System.ValueTuple. To workaround it till MS releases the fix, downgrade the

import MySQLdb db = MySQLdb.connect("localhost","root","password","database") cursor = db.cursor() cursor.execute("SELECT id FROM some_table") u_data = cursor.fetchall() >>> print u_data ((1320088L,),) What I found on internet got me till here: string = ((1320088L,),) string = ','.join(map(str, string)) >>> print string (1320088L,) what I expect output to look like: #Single element expected result 1320088L #comma separated list if more than 2 elements, below is an example 1320088L,1320089L Use itertools.chain_fromiterable() to flatten your nested tuples first, then map() to string and join() .

I have a dataframe that looks like the following user item \ 0 b80344d063b5ccb3212f76538f3d9e43d87dca9e The Cove - Jack Johnson 1 b80344d063b5ccb3212f76538f3d9e43d87dca9e Entre Dos Aguas - Paco De Lucia 2 b80344d063b5ccb3212f76538f3d9e43d87dca9e Stronger - Kanye West 3 b80344d063b5ccb3212f76538f3d9e43d87dca9e Constellations - Jack Johnson 4 b80344d063b5ccb3212f76538f3d9e43d87dca9e Learn To Fly - Foo Fighters rating 0 1 1 2 2 1 3 1 4 1 and would like to achieve the following structure: dict-> list of tuples user-> (item, rating) b80344d063b5ccb3212f76538f3d9e43d87dca9e -> list((The Cove - Jack

Given a list of tuples like so: a = [ ( "x", 1, ), ( "x", 2, ), ( "y", 1, ), ( "y", 3, ), ( "y", 4, ) ] What would be the easiest way to filter for unique first element and merge the second element. An output like so would be desired. b = [ ( "x", 1, 2 ), ( "y", 1, 3, 4 ) ] Thanks, You can use a defaultdict : >>> from collections import defaultdict >>> d = defaultdict(tuple) >>> a = [('x', 1), ('x', 2), ('y', 1), ('y', 3), ('y', 4)] >>> for tup in a: ... d[tup[0]] += (tup[1],) ... >>> [tuple(x for y in i for x in y) for i in d.items()] [('y', 1, 3, 4), ('x', 1, 2)] >>> a = [("x", 1,), ("x", 2,

Using pandas, I have exported to a csv file a dataframe whose cells contain tuples of strings. The resulting file has the following structure: index,colA 1,"('a','b')" 2,"('c','d')" Now I want to read it back using read_csv. However whatever I try, pandas interprets the values as strings rather than tuples. For instance: In []: import pandas as pd df = pd.read_csv('test',index_col='index',dtype={'colA':tuple}) df.loc[1,'colA'] Out[]: "('a','b')" Is there a way of telling pandas to do the right thing? Preferably without heavy post-processing of the dataframe: the actual table has 5000 rows and

#include <iostream> #include <tuple> int main(){ auto bt=std::make_tuple(std::tuple<>(),std::tuple<std::tuple<>>()); //Line 1 auto bt2=std::make_tuple(std::tuple<>(),std::tuple<>()); //Line 2 } Why does Line 1 gives a compile error while Line 2 compiles fine? (tested in both Gcc&Clang) Is there a possible workaround? error message for clang /usr/include/c++/4.6/tuple:150:50: error: ambiguous conversion from derived class 'std::_Tuple_impl<0, std::tuple<>, std::tuple<std::tuple<> > >' to base class 'std::_Head_base<0, std::tuple<>, true>': struct std::_Tuple_impl<0, class std::tuple<>, class

I have the following ADO Model Student Id,Name and Course Id,Name,Student_ID I have made the following view for it @model Tuple<MvcApplication4.Models.Course, MvcApplication4.Models.Student > @{ ViewBag.Title = "Create"; } <h2>Create</h2> @using (Html.BeginForm()) { @Html.ValidationSummary(true) <fieldset> <legend>Course</legend> <div class="editor-label"> @Html.LabelFor(model => model.Item1.Name) </div> <div class="editor-field"> @Html.EditorFor(model => model.Item1.Name) @Html.ValidationMessageFor(model => model.Item1.Name) </div> <div class="editor-label"> @Html.LabelFor(model => model