def minify_js_files():
    """
        This command minified js files with UglifyJS
    """
    for k, v in JS_FILE_MAPPING.items():
        input_files = " ".join(v["input_files"])
        output_file = v["output_file"]

        uglifyjs_command = "uglifyjs {input_files} -o {output_file}".format(
            input_files=input_files,
            output_file=output_file
        )
        local(uglifyjs_command)
This command minified js files with UglifyJS