Sanitize the column names in CLI (dotnet#162)

* added sanitization layer in CLI

* fix test

* changed exception.StackTrace to exception.ToString()

Author: srsaggam

src/Microsoft.ML.Auto/ColumnInference/ColumnTypeInference.cs

@@ -76,7 +76,8 @@ public IntermediateColumn(ReadOnlyMemory<char>[] data, int columnId)
             public bool HasAllBooleanValues()
             {
                 if (this.RawData.Skip(1)
-                    .All(x => {
+                    .All(x =>
+                    {
                         bool value;
                         // (note: Conversions.TryParse parses an empty string as a Boolean)
                         return !string.IsNullOrEmpty(x.ToString()) &&
@@ -358,7 +359,7 @@ private static InferenceResult InferTextFileColumnTypesCore(MLContext env, IMult
             var labelColumn = GetAndValidateLabelColumn(args, cols);
 
             // if label column has all Boolean values, set its type as Boolean
-            if(labelColumn.HasAllBooleanValues())
+            if (labelColumn.HasAllBooleanValues())
             {
                 labelColumn.SuggestedType = BoolType.Instance;
             }
@@ -371,13 +372,7 @@ private static InferenceResult InferTextFileColumnTypesCore(MLContext env, IMult
         private static string SuggestName(IntermediateColumn column, bool hasHeader)
         {
             var header = column.RawData[0].ToString();
-            return (hasHeader && !string.IsNullOrWhiteSpace(header)) ? Sanitize(header) : string.Format("col{0}", column.ColumnId);
-        }
-
-        private static string Sanitize(string header)
-        {
-            // replace all non-letters and non-digits with '_'.
-            return string.Join("", header.Select(x => Char.IsLetterOrDigit(x) ? x : '_'));
+            return (hasHeader && !string.IsNullOrWhiteSpace(header)) ? header : string.Format("col{0}", column.ColumnId);
         }
 
         private static IntermediateColumn GetAndValidateLabelColumn(Arguments args, IntermediateColumn[] cols)

src/Test/ColumnInferenceTests.cs

@@ -44,10 +44,10 @@ public void InferColumnsLabelIndex()
             var result = new MLContext().Data.InferColumns(DatasetUtil.DownloadUciAdultDataset(), 14, hasHeader: true);
             Assert.AreEqual(true, result.TextLoaderArgs.HasHeader);
             var labelCol = result.TextLoaderArgs.Column.First(c => c.Source[0].Min == 14 && c.Source[0].Max == 14);
-            Assert.AreEqual("hours_per_week", labelCol.Name);
+            Assert.AreEqual("hours-per-week", labelCol.Name);
             var labelPurposes = result.ColumnPurpopses.Where(c => c.Purpose == ColumnPurpose.Label);
             Assert.AreEqual(1, labelPurposes.Count());
-            Assert.AreEqual("hours_per_week", labelPurposes.First().Name);
+            Assert.AreEqual("hours-per-week", labelPurposes.First().Name);
         }
 
         [TestMethod]

src/mlnet/Commands/New/NewCommandHandler.cs

@@ -5,6 +5,7 @@
 using System;
 using System.Collections.Generic;
 using System.IO;
+using System.Linq;
 using Microsoft.Data.DataView;
 using Microsoft.ML.Auto;
 using Microsoft.ML.CLI.CodeGenerator.CSharp;
@@ -32,6 +33,8 @@ public void Execute()
             // Infer columns
             (TextLoader.Arguments TextLoaderArgs, IEnumerable<(string Name, ColumnPurpose Purpose)> ColumnPurpopses) columnInference = InferColumns(context);
 
+            Array.ForEach(columnInference.TextLoaderArgs.Column, t => t.Name = Sanitize(t.Name));
+
             // Load data
             (IDataView trainData, IDataView validationData) = LoadData(context, columnInference.TextLoaderArgs);
 
@@ -45,7 +48,7 @@ public void Execute()
             catch (Exception e)
             {
                 logger.Log(LogLevel.Error, $"{Strings.ExplorePipelineException}:");
-                logger.Log(LogLevel.Error, e.StackTrace);
+                logger.Log(LogLevel.Error, e.ToString());
                 logger.Log(LogLevel.Error, Strings.Exiting);
                 return;
             }
@@ -157,5 +160,9 @@ internal static void SaveModel(ITransformer model, string ModelPath, string mode
                 model.SaveTo(mlContext, fs);
         }
 
+        private static string Sanitize(string name)
+        {
+            return string.Join("", name.Select(x => Char.IsLetterOrDigit(x) ? x : '_'));
+        }
     }
 }