c# - Error on CSV to Dictionary -

not sure why isn't working, it's adapted code work. looks need explicit cast i'm not sure why or put it. error is:

"cannot implicitly convert type 'system.collections.generic.ienumerable{system.collections.generic.dictionary{string,string}}' 'system.collections.generic.dictionary{string,string}'"

    public static dictionary<string, string> data_entry(string dataentity, string datacategory, string datastream = "")     {         var lines = file.readalllines(@"c:\myfile.csv");         var header = lines.first().split(',');         return (from line in lines.skip(1)             let cols = line.split(',')             cols[0].toupper() == dataentity & cols[1].toupper() == datacategory & cols[4].toupper() == datastream             select header.select((h, i) => new { header = h, index = })             .todictionary(o => o.header, o => cols[o.index])         );     } 

your linq query returning ienumerable<t> object t of type dictionary instead of expecting dictionary.

if understand code want create list of dictionaries column header key , line's column index value value. since dictionaries cannot have duplicate keys, can't turn entire thing 1 dictionary object there exceptions duplicate keys.

so want pull todictionary() call out of linq statement , apply result of linq statement instead dictionary. unfortunately, result in said duplicate key errors way it's coded instead of returning dictionary might consider different datastructure or change return type ienumerable<dictionary<string,string>> type.

edit: based on follow-up information in comments following need be. notice added firstordefault() call results of linq query. means return first result (which type dictionary<string,string>) satisfies method's return type. it's worth having check in calling code null return in case if you're confident never null.

public static dictionary<string, string> data_entry(string dataentity, string datacategory, string datastream = "") {     var lines = file.readalllines(@"c:\myfile.csv");     var header = lines.first().split(',');     return (from line in lines.skip(1)         let cols = line.split(',')         cols[0].toupper() == dataentity & cols[1].toupper() == datacategory & cols[4].toupper() == datastream         select header.select((h, i) => new { header = h, index = })         .todictionary(o => o.header, o => cols[o.index])     ).firstordefault(); }