There are some problems to parse the ouput of executing Ansible playbooks:

1. If don't set the parameter universal_newlines to True for p = subprocess.Popen(), the return value of p.communicate() is bytes not str for Python3;
2. Parse string like "ok=6 changed=5 unreachable=0 failed=0 skipped=3 rescued=0 ignored=0" error, and can't get the right value of failed_flag.