@app.after_request
def add_header(request):
    request.headers['Cache-Control'] = 'no-cache, no-store, must-revalidate'
    request.headers['Pragma'] = 'no-cache'
    request.headers['Expires'] = '0'
    request.headers['Cache-Control'] = 'public, max-age=0'
    return request
@app.after_request
def add_header(request):
    request.headers['Cache-Control'] = 'no-cache, no-store, must-revalidate'
    request.headers['Pragma'] = 'no-cache'
    request.headers['Expires'] = '0'
    request.headers['Cache-Control'] = 'public, max-age=0'
    return request