Python CGI File Download Issue

I was facing issues in making a Python CGI script which downloads a file. When I run my script, the file does get downloaded, but when I open the downloaded file, it says it has zero bytes in it.

This is the HTML snippet that calls the download file in my main Python CGI File

html += """
            <form enctype = "multipart/form-data" action = "download_file.py" method = "get" class='file'>
                <h3>%s</h3>
                <h4>File name: %s</h4>
                <input type='hidden' value=%s name='fname'>
                <h3 class='btn btn-info'><a href="%s" download>Download File</a></h3>
            </form>
        """ % (str(i+1), str(files[i]['name']), str(files[i]['name']), str(os.path.join('tmp', files[i]['name'])))

And this is the code inside download_file.py

import cgi, os
form = cgi.FieldStorage()

filename = form['fname'].value
fullpath = open(os.path.join('cgi-bin', 'tmp', str(filename)), "rb")

print('Content-Type:application/octet-stream; name="%s"' % filename)
print('Content-Disposition: attachment; filename="%s"' % filename)
print("")

with open(filename, 'rb') as fo:
    print(open(filename).read())
    fo.close()

I hope you could help me in resolving this issue!