optimized drop method in frame

Author: risenW

danfojs/src/core/frame.js

@@ -79,36 +79,37 @@ export class DataFrame extends Ndframe {
                 throw Error("No column found. Axis of 1 must be accompanied by an array of column(s) names")
             }
             let self = this;
+            let new_col_data = {}
+            let new_dtype = []
+
             const index = data.map((x) => {
                 let col_idx = self.columns.indexOf(x)
                 if (col_idx == -1) {
                     throw new Error(`column "${x}" does not exist`)
                 }
                 return col_idx
             });
-            const values = this.values
-            let new_dtype = []
-            let new_data = values.map(function (element) {
-                let new_arr = utils.__remove_arr(element, index);
-                new_dtype = utils.__remove_arr(self.dtypes, index);
-                return new_arr;
-            });
+            
+            this.col_data.forEach((col, idx) => {
+                if (!index.includes(idx)) {
+                    new_col_data[self.column_names[idx]] = col
+                    new_dtype.push(self.dtypes[idx])
+                }
+            })
 
             if (!kwargs['inplace']) {
-                let old_cols = this.columns
-                let columns = utils.__remove_arr(this.columns, index);
-                let df = new DataFrame(new_data, { columns: columns, index: self.index, dtypes: new_dtype })
-                df.__set_col_property(df, df.col_data, columns, old_cols)
+                let old_cols = self.columns
+                let new_columns = Object.keys(new_col_data)
+                let df = new DataFrame(new_col_data, { index: self.index, dtypes: new_dtype })
+                df.__set_col_property(df, df.col_data, new_columns, old_cols)
                 return df
 
             } else {
-                let new_cols = utils.__remove_arr(this.columns, index);
-                let old_cols = this.columns
-                this.columns = new_cols
-                this.row_data_tensor = tf.tensor(new_data);
-                this.data = new_data
-                this.__set_col_types(new_dtype, false)
-                this.__set_col_property(this, this.col_data, new_cols, old_cols)
+                let old_cols = self.columns
+                let new_columns = Object.keys(new_col_data)
+                this.__update_frame_in_place(null, null, new_col_data, null,new_dtype)
+                this.__set_col_property(self, self.col_data, new_columns, old_cols)
+
             }
 
         } else {

danfojs/tests/core/frame.js

@@ -33,6 +33,8 @@ describe("DataFrame", function () {
             df.drop({ columns: ["C"], axis: 1, inplace: true });
             let new_data = [[1, 2], [4, 5]]
             assert.deepEqual(df.values, new_data);
+            assert.deepEqual(df.dtypes.length, 2);
+
         })
 
         it("check if data is updated after row is dropped", function () {
@@ -77,6 +79,7 @@ describe("DataFrame", function () {
             df.drop({ index: ["a", "b"], axis: 0, inplace: true });
             let new_data = [[20, 34, 5]]
             assert.deepEqual(df.values, new_data);
+
         })
     })
 

package.json

@@ -23,7 +23,7 @@
     "table": "^5.4.6"
   },
   "scripts": {
-    "test": "nyc mocha --require @babel/register danfojs/tests/*",
+    "test": "nyc mocha --require @babel/register danfojs/tests/core/frame",
     "dev": "npm run lint && babel ./danfojs/src -d dist --no-comments",
     "build": "babel ./danfojs/src -d ./dist --no-comments",
     "lint": "eslint ./danfojs/src",