终于可以pip install virtualenv，但是创建virtualenv实例的时候又包了这个问题，请问咋解决，谢啦
[deploy@localhost ~]$ virtualenv -p /usr/local/bin/python3.6 .py3-a2.5-env
Traceback (most recent call last):
File “/usr/local/bin/virtualenv”, line 7, in
from virtualenv.main import run_with_catch
File “/usr/local/lib/python3.6/site-packages/virtualenv/init.py”, line 3, in
from .run import cli_run, session_via_cli
File “/usr/local/lib/python3.6/site-packages/virtualenv/run/init.py”, line 11, in
from …seed.wheels.periodic_update import manual_upgrade
File “/usr/local/lib/python3.6/site-packages/virtualenv/seed/wheels/init.py”, line 3, in
from .acquire import get_wheel, pip_wheel_env_run
File “/usr/local/lib/python3.6/site-packages/virtualenv/seed/wheels/acquire.py”, line 12, in
from .bundle import from_bundle
File “/usr/local/lib/python3.6/site-packages/virtualenv/seed/wheels/bundle.py”, line 4, in
from .periodic_update import periodic_update
File “/usr/local/lib/python3.6/site-packages/virtualenv/seed/wheels/periodic_update.py”, line 10, in
import ssl
File “/usr/local/lib/python3.6/ssl.py”, line 101, in
import _ssl # if we can’t import it, let the error propagate
ModuleNotFoundError: No module named ‘_ssl’
[deploy@localhost ~]$