Fixes #569

Author: acctsi1

src/danfojs-base/io/browser/io.csv.ts

@@ -160,7 +160,7 @@ const $toCSV = (df: NDframe | DataFrame | Series, options?: CsvOutputOptionsBrow
  */
 const $downloadFileInBrowser = (content: any, fileName: string) => {
   var hiddenElement = document.createElement('a');
-  hiddenElement.href = 'data:text/csv;charset=utf-8,' + encodeURI(content);
+  hiddenElement.href = 'data:text/csv;charset=utf-8,' + encodeURIComponent(content);
   hiddenElement.target = '_blank';
   hiddenElement.download = fileName;
   hiddenElement.click();

src/danfojs-base/io/browser/io.json.ts

@@ -174,7 +174,7 @@ const $toJSON = (df: NDframe | DataFrame | Series, options?: JsonOutputOptionsBr
  */
 const $downloadFileInBrowser = (content: any, fileName: string) => {
     var hiddenElement = document.createElement('a');
-    hiddenElement.href = 'data:text/json;charset=utf-8,' + encodeURI(JSON.stringify(content));
+    hiddenElement.href = 'data:text/json;charset=utf-8,' + encodeURIComponent(JSON.stringify(content));
     hiddenElement.target = '_blank';
     hiddenElement.download = fileName;
     hiddenElement.click();