Example of calling an application

An example of calling an application and retrieving its response:

def call_application(app, environ):
    body = []
    status_headers = [None, None]
    def start_response(status, headers):
        status_headers[:] = [status, headers]
        return body.append(status_headers)
    app_iter = app(environ, start_response)
    try:
        for item in app_iter:
            body.append(item)
    finally:
        if hasattr(app_iter, 'close'):
            app_iter.close()
    return status_headers[0], status_headers[1], ''.join(body)
 
status, headers, body = call_application(app, {...environ...})