正文
解决 Flask 项目无法用 .env 文件中解析的参数设置环境变量的错误
提示：扫一扫查出行【扫一扫了解最新限行尾号】
复制提示
在 Windows 上启动 Flask 项目时，工作目录有 UTF-8 编码的 .env 文件，里面配置的环境变量在 Python2 中识别为 Unicode 类型，导致下述错误：
* Serving Flask app "bootstrap" (lazy loading)
* Environment: development
* Debug mode: on
* Restarting with stat
Traceback (most recent call last):
File "bootstrap.py", line 40, in <module>
app.run(host=str(settings.DEV_HOST), port=settings.DEV_PORT)
File "D:\Python27\lib\site-packages\flask\app.py", line 943, in run
run_simple(host, port, self, **options)
File "D:\Python27\lib\site-packages\werkzeug\serving.py", line 812, in run_simple
reloader_type)
File "D:\Python27\lib\site-packages\werkzeug\_reloader.py", line 275, in run_with_reloader
sys.exit(reloader.restart_with_reloader())
File "D:\Python27\lib\site-packages\werkzeug\_reloader.py", line 132, in restart_with_reloader
close_fds=False)
File "D:\Python27\lib\subprocess.py", line 172, in call
return Popen(*popenargs, **kwargs).wait()
File "D:\Python27\lib\subprocess.py", line 394, in __init__
errread, errwrite)
File "D:\Python27\lib\subprocess.py", line 644, in _execute_child
startupinfo)
TypeError: environment can only contain strings
遇到这种情况，只需对 werkzeug 项目做个小的修改即可。Diff 文件如下所示：
diff --git a/werkzeug/_reloader.backup.py b/werkzeug/_reloader.py
# index 0d23dba..2698040 100644
# --- a/_reloader.backup.py
# +++ b/_reloader.py
# @@ -117,16 +117,20 @@ class ReloaderLoop(object):
# while 1:
# _log('info', ' * Restarting with %s' % self.name)
# args = _get_args_for_reloading()
# - new_environ = os.environ.copy()
# - new_environ['WERKZEUG_RUN_MAIN'] = 'true'
# + old_environ = os.environ.copy()
# + new_environ = {
# + 'WERKZEUG_RUN_MAIN': 'true'
# + }
#
# # a weird bug on windows. sometimes unicode strings end up in the
# # environment and subprocess.call does not like this, encode them
# # to latin1 and continue.
# if os.name == 'nt' and PY2:
# - for key, value in iteritems(new_environ):
# + for key, value in iteritems(old_environ):
# if isinstance(value, text_type):
# - new_environ[key] = value.encode('iso-8859-1')
# + new_environ[key.encode('iso-8859-1')] = value.encode('iso-8859-1')
# + else:
# + new_environ[key] = value
#
# exit_code = subprocess.call(args, env=new_environ,
# close_fds=False)
