rename implemented for frame and series

.flowconfig

@@ -1,6 +1,13 @@
 [options]
 unsafe.enable_getters_and_setters=true
 suppress_comment=.*\\$FlowIssue
+module.system.node.resolve_dirname=src
+module.system.node.resolve_dirname=node_modules
 
 [ignore]
-.*\.json
+.*/.json
+.*/__tests__/.*
+.*/node_modules/fbjs/.*
+
+[libs]
+node_modules/immutable/dist/immutable.js.flow

src/es6/__tests__/core/frame.js

@@ -1000,4 +1000,18 @@ describe('frame', () => {
       console.log(df.pivot_table(['a', 'b'], 'c', 'd'));
     });
   });
+
+  describe('rename', () => {
+    it('renames one Series in the DataFrame', () => {
+      const df = new DataFrame(
+        [{x: 1, y: 2}, {x: 2, y: 3}, {x: 3, y: 4}], {index: [1, 2, 3]});
+      const df2 = df.rename({columns: Immutable.Map({x: 'q'})});
+
+      expect(df.columns.toArray()).toEqual(['x', 'y']);
+      expect(df2.columns.toArray()).toEqual(['q', 'y']);
+      expect(df2.get('q').values.toArray()).toEqual([1, 2, 3]);
+      expect(df2.get('q').index.toArray()).toEqual([1, 2, 3]);
+      expect(df2.get('q').name).toEqual('q');
+    });
+  });
 });

src/es6/__tests__/core/series.js

@@ -37,9 +37,7 @@ describe('series', () => {
       expect(ds2).toBeInstanceOf(Series);
       expect(ds2.values.toArray()).toEqual([1, 2, 3, 4]);
 
-      ds2.name = 'test';
       expect(ds1.name).toEqual('Test name');
-      expect(ds2.name).toEqual('test');
 
       ds2.index = [1, 2, 3, 4];
       expect(ds1.index.toArray()).toEqual([2, 3, 4, 5]);
@@ -52,6 +50,14 @@ describe('series', () => {
       expect(ds.shape.toArray()).toEqual([5]);
     });
 
+    it('rename', () => {
+      const ds = new Series([1, 2, 3], {name: 'test name'});
+      expect(ds.name).toEqual('test name');
+      const ds2 = ds.rename('test name 2');
+      expect(ds.name).toEqual('test name');
+      expect(ds2.name).toEqual('test name 2');
+    });
+
     describe('astype', () => {
       it('converts a float Series to an integer Series', () => {
         const ds1 = new Series([1.5, 2.1, 3.9]);

src/es6/core/frame.js

@@ -3,7 +3,6 @@
  * DataFrame object
  */
 
-// $FlowIssue
 import Immutable from 'immutable';
 // import { saveAs } from 'file-saver'; TODO figure out if best way
 
@@ -267,8 +266,7 @@ export default class DataFrame extends NDFrame {
       const prevColumn = this.columns.get(idx);
       const prevSeries = this.get(prevColumn);
 
-      prevSeries.name = k;
-      nextData[k] = prevSeries;
+      nextData[k] = prevSeries.rename(k);
     });
 
     this._data = Immutable.Map(nextData);
@@ -1546,6 +1544,23 @@ export default class DataFrame extends NDFrame {
   cummin(axis: number = 0): DataFrame {
     return this._cumulativeHelper(OP_CUMMIN, axis);
   }
+
+  /**
+   * Rename the `DataFrame` and return a new DataFrame
+   *
+   * pandas equivalent: [DataFrame.rename](http://pandas.pydata.org/pandas-docs/stable/generated/pandas.DataFrame.rename.html)
+   *
+   * @param {Immutable.Map} columns
+   * @returns {DataFrame}
+   */
+  rename({ columns }: {columns: Immutable.Map}): DataFrame {
+    return new DataFrame(Immutable.OrderedMap(this.columns.map((prevCol) => {
+      const nextCol = columns.get(prevCol);
+      if (typeof nextCol === 'undefined')
+        return [prevCol, this._data.get(prevCol)];
+      return [nextCol, this._data.get(prevCol).rename(nextCol)];
+    })), {index: this.index});
+  }
 }
 
 const innerMerge = (df1: DataFrame, df2: DataFrame, on: Array<string|number>): DataFrame => {

src/es6/core/series.js

@@ -4,7 +4,6 @@
  * numpy.ndarray as the values
  */
 
-// $FlowIssue
 import Immutable from 'immutable';
 
 import NDFrame from './generic';
@@ -59,7 +58,7 @@ export default class Series extends NDFrame {
       this._dtype = arrayToDType([data]);
     }
 
-    this.name = typeof kwargs.name !== 'undefined' ? kwargs.name : '';
+    this._name = typeof kwargs.name !== 'undefined' ? kwargs.name : '';
 
     this.set_axis(0, parseIndex(kwargs.index, this.values));
     this._setup_axes(Immutable.List.of(0));
@@ -287,6 +286,15 @@ export default class Series extends NDFrame {
     return super.values;
   }
 
+  /**
+   * Return the name of the `Series`
+   *
+   * @returns {string}
+   */
+  get name(): string {
+    return this._name;
+  }
+
   /**
    * Convert the series to the desired type
    *
@@ -488,7 +496,7 @@ export default class Series extends NDFrame {
       return this.map(v => v + val);
     else if (val instanceof Series) // $FlowIssue TODO
       return this.map((v, idx) => v + val.iloc(idx));
-    else if (Array.isArray(val)) // $FlowIssue TODO
+    else if (Array.isArray(val))
       return this.map((v, idx) => v + val[idx]);
     else if (val instanceof Immutable.List) // $FlowIssue TODO
       return this.map((v, idx) => v + val.get(idx));
@@ -845,11 +853,11 @@ export default class Series extends NDFrame {
     this.index.forEach((idx1) => {
       if (!(seriesAlignment.has(idx1))) {
         seriesAlignment = seriesAlignment
-          .set(idx1, Immutable.Map({ // $FlowIssue TODO
+          .set(idx1, Immutable.Map({
             first: Immutable.List.of(this.iloc(idx1)),
             second: Immutable.List([]),
           }));
-      } else { // $FlowIssue TODO
+      } else {
         seriesAlignment = seriesAlignment.updateIn([idx1, 'first'], l => l.concat(this.iloc(idx1)));
       }
     });
@@ -858,11 +866,11 @@ export default class Series extends NDFrame {
       if (!(seriesAlignment.has(idx2))) {
         seriesAlignment = seriesAlignment
           .set(idx2, Immutable.Map({
-            first: Immutable.List([]), // $FlowIssue TODO
+            first: Immutable.List([]),
             second: Immutable.List.of(series.iloc(idx2)),
           }));
       } else {
-        seriesAlignment = seriesAlignment.updateIn([idx2, 'second'], // $FlowIssue TODO
+        seriesAlignment = seriesAlignment.updateIn([idx2, 'second'],
           l => l.concat(series.iloc(idx2)));
       }
     });
@@ -1301,4 +1309,21 @@ export default class Series extends NDFrame {
         throw new TypeError(`orient must be in ${ALLOWED_ORIENT}`);
     }
   }
+
+  /**
+   * Rename the `Series` and return a new `Series`
+   *
+   * pandas equivalent: [Series.rename](http://pandas.pydata.org/pandas-docs/stable/generated/pandas.Series.rename.html)
+   *
+   * @param {string} name
+   *
+   * @example
+   * const ds = new Series([1, 2, 3], {name: 'Test name'});
+   * ds.rename('New test name');
+   * // returns 'New test name'
+   * ds.name;
+   */
+  rename(name: string): Series {
+    return new Series(this._values, {name, index: this.index});
+  }
 }