flask-的markupsafe缺失

运行时出现markupsafe._compat的错误

解决方法
原因：发现少了_compat.py 的文件
在网上搜索发现文件内容如下：

-- coding: utf-8 --

“””
markupsafe._compat
~~~~~~~~~~~~~~
Compatibility module for different Python versions.
:copyright: (c) 2013 by Armin Ronacher.
:license: BSD, see LICENSE for more details.
“””
import sys
PY2 = sys.version_info[0] == 2
if not PY2:
text_type = str
string_types = (str,)
unichr = chr
int_types = (int,)
iteritems = lambda x: iter(x.items())
else:
text_type = unicode
string_types = (str, unicode)
unichr = unichr
int_types = (int, long)
iteritems = lambda x: x.iteritems()

缺少文件，就自己创建文件