writeCsv() with row names

src/main/java/joinery/DataFrame.java

@@ -2172,9 +2172,23 @@ public static final DataFrame<Object> readCsv(final InputStream input, final Str
      * @param file the file to write
      * @throws IOException if an error occurs writing the file
      */
+    // CS427 Issue link: https://github.com/cardillo/joinery/issues/51
     public final void writeCsv(final String file)
     throws IOException {
-        Serialization.writeCsv(this, new FileOutputStream(file));
+        Serialization.writeCsv(this, file);
+    }
+
+    /**
+     * Write the data from this data frame to the specified file as csv.
+     *
+     * @param file the file to write
+     * @param writeRowNames whether to include row names
+     * @throws IOException if an error occurs writing the file
+     */
+    // CS427 Issue link: https://github.com/cardillo/joinery/issues/51
+    public final void writeCsv(final String file, final boolean writeRowNames)
+            throws IOException {
+        Serialization.writeCsv(this, file, writeRowNames);
     }
 
     /**
@@ -2184,11 +2198,25 @@ public final void writeCsv(final String file)
      * @param output
      * @throws IOException
      */
+    // CS427 Issue link: https://github.com/cardillo/joinery/issues/51
     public final void writeCsv(final OutputStream output)
     throws IOException {
         Serialization.writeCsv(this, output);
     }
 
+    /**
+     * Write the data from this data frame to the provided output stream as csv.
+     *
+     * @param output
+     * * @param writeRowNames whether to include row names
+     * @throws IOException
+     */
+    // CS427 Issue link: https://github.com/cardillo/joinery/issues/51
+    public final void writeCsv(final OutputStream output, final boolean writeRowNames)
+            throws IOException {
+        Serialization.writeCsv(this, output, writeRowNames);
+    }
+
     /**
      * Read data from the specified excel
      * workbook into a new data frame.

src/main/java/joinery/impl/Serialization.java

@@ -42,6 +42,7 @@
 import java.util.Iterator;
 import java.util.List;
 import java.util.Map;
+import java.util.Collection;
 
 import org.apache.poi.hssf.usermodel.HSSFDataFormat;
 import org.apache.poi.hssf.usermodel.HSSFWorkbook;
@@ -290,14 +291,83 @@ public static DataFrame<Object> readCsv(final InputStream input, String separato
         }
     }
 
+    /**
+     * Write the data from data frame to the specified file as csv with no row names.
+     *
+     * @param output the file to write to
+     * @param df data frame to write from
+     * @throws IOException if an error occurs writing the file
+     */
     public static <V> void writeCsv(final DataFrame<V> df, final String output)
     throws IOException {
         writeCsv(df, new FileOutputStream(output));
     }
 
+    /**
+     * Write the data from data frame to the specified file as csv.
+     *
+     * @param output the file to write to
+     * @param df data frame to write from
+     * @param writeRowNames whether to include row names
+     * @throws IOException if an error occurs writing the file
+     */
+    // CS427 Issue link: https://github.com/cardillo/joinery/issues/51
+    public static <V> void writeCsv(final DataFrame<V> df, final String output, final boolean writeRowNames)
+            throws IOException {
+        writeCsv(df, new FileOutputStream(output), writeRowNames);
+    }
+
+    /**
+     * Write the data from data frame to the specified file as csv with no row names.
+     *
+     * @param output the file to write to
+     * @param df data frame to write from
+     * @throws IOException if an error occurs writing the file
+     */
+    // CS427 Issue link: https://github.com/cardillo/joinery/issues/51
     public static <V> void writeCsv(final DataFrame<V> df, final OutputStream output)
-    throws IOException {
+            throws IOException {
+        writeCsv(df, output, false);
+    }
+
+    /**
+     * Add row names to data frame as the
+     * first column.
+     *
+     * @param df data frame to add to
+     * @return data frame with the row names
+     */
+    // CS427 Issue link: https://github.com/cardillo/joinery/issues/51
+    public static <V> DataFrame<V> addRowNames(final DataFrame<V> df) {
+        DataFrame<V> dff = new DataFrame<>();
+        final List<V> indexes = new ArrayList<>((Collection<? extends V>) df.index());
+        dff.add("", indexes);
+        dff = df.join(dff, DataFrame.JoinType.RIGHT);
+        for (int c = 0; c < df.size(); c++) {
+            final int sizeOfCol = df.length();
+            for (int r = 0; r < sizeOfCol; r++) {
+                dff.set(r, c+1, df.get(r, c));
+            }
+        }
+        return dff;
+    }
+
+    /**
+     * Write the data from data frame to the specified file as csv.
+     *
+     * @param output the file to write to
+     * @param df data frame to write from
+     * @param writeRowNames whether to include row names
+     * @throws IOException if an error occurs writing the file
+     */
+    // CS427 Issue link: https://github.com/cardillo/joinery/issues/51
+    public static <V> void writeCsv(final DataFrame<V> df, final OutputStream output, final boolean writeRowNames)
+            throws IOException {
         try (CsvListWriter writer = new CsvListWriter(new OutputStreamWriter(output), CsvPreference.STANDARD_PREFERENCE)) {
+            if (writeRowNames) {
+                writeCsv(addRowNames(df), output, false);
+                return;
+            }
             final String[] header = new String[df.size()];
             final Iterator<Object> it = df.columns().iterator();
             for (int c = 0; c < df.size(); c++) {

src/test/java/joinery/DataFrameSerializationTest.java

@@ -176,7 +176,7 @@ public void testReadWriteCsvTypes()
             );
     }
 
-    @Test
+    @Test // CS427 Issue link: https://github.com/cardillo/joinery/issues/51
     public void testWriteCsvNonStringIndex()
     throws IOException {
         final ByteArrayOutputStream out = new ByteArrayOutputStream();
@@ -186,6 +186,65 @@ public void testWriteCsvNonStringIndex()
         assertTrue("writeCsv does not throw due to non-string indices", true);
     }
 
+    /**
+     * Test to write a csv with row names enabled
+     *
+     * @throws IOException if an error occurs writing the file
+     */
+    @Test // CS427 Issue link: https://github.com/cardillo/joinery/issues/51
+    public void testWriteCsvWithRowNames()
+            throws IOException {
+        df = new DataFrame<>(
+                Arrays.<Object>asList("row1", "row2", "row3", "row4", "row5", "row6"),
+                Arrays.<Object>asList("category", "name", "value"),
+                Arrays.asList(
+                        Arrays.<Object>asList("a", "a", "b", "b", "c", "c"),
+                        Arrays.<Object>asList("alpha", "bravo", "charlie", "delta", "echo", "foxtrot"),
+                        Arrays.<Object>asList(1, 2, 3, 4, 5, 6)
+                )
+        );
+        final File tmp = File.createTempFile(getClass().getName(), ".csv");
+        tmp.deleteOnExit();
+        df.writeCsv(tmp.getPath(), true);
+        for (int i = 0; i < df.size() + 1; i++) {
+            assertArrayEquals(
+                    "Checking if reading the csv has the row names",
+                    DataFrame.readCsv(ClassLoader.getSystemResourceAsStream("serialization_row_names.csv")).col(0).toArray(),
+                    DataFrame.readCsv(tmp.getPath()).col(0).toArray()
+            );
+        }
+    }
+
+
+    /**
+     * Test to write a csv with row names disabled
+     *
+     * @throws IOException if an error occurs writing the file
+     */
+    @Test // CS427 Issue link: https://github.com/cardillo/joinery/issues/51
+    public void testWriteCsvWithoutRowNames()
+            throws IOException {
+        df = new DataFrame<>(
+                Arrays.<Object>asList("row1", "row2", "row3", "row4", "row5", "row6"),
+                Arrays.<Object>asList("category", "name", "value"),
+                Arrays.asList(
+                        Arrays.<Object>asList("a", "a", "b", "b", "c", "c"),
+                        Arrays.<Object>asList("alpha", "bravo", "charlie", "delta", "echo", "foxtrot"),
+                        Arrays.<Object>asList(1, 2, 3, 4, 5, 6)
+                )
+        );
+        final File tmp = File.createTempFile(getClass().getName(), ".csv");
+        tmp.deleteOnExit();
+        df.writeCsv(new FileOutputStream(tmp), false);
+        for (int i = 0; i < df.size(); i++) {
+            assertArrayEquals(
+                    "Checking if reading the csv does not have the row names",
+                    DataFrame.readCsv(ClassLoader.getSystemResourceAsStream("serialization.csv")).col(0).toArray(),
+                    DataFrame.readCsv(tmp.getPath()).col(0).toArray()
+            );
+        }
+    }
+
     @Test(expected=FileNotFoundException.class)
     public void testReadXlsString()
     throws IOException {

src/test/resources/serialization_row_names.csv

@@ -0,0 +1,7 @@
+,category,name,value
+row1,a,alpha,1
+row2,a,bravo,2
+row3,b,charlie,3
+row4,b,delta,4
+row5,c,echo,5
+row6,c,foxtrot,6