def helper_not_here():
 html = u'<!DOCTYPE html>\n    <html>\n        <head>\n            <title>Hello from Flask</title>\n        </head>\n        <body>Hello World, {{ h.nohere() }} no helper here</body>\n    </html>'
 return render_template_string(html)

def helper_not_here ( ) : html = u'<!DOCTYPE html>\n    <html>\n        <head>\n            <title>Hello from Flask</title>\n        </head>\n        <body>Hello World, {{ h.nohere() }} no helper here</body>\n    </html>' return render_template_string ( html )
a simple template with a helper that doesnt exist .