第一章 page14页，运行不了程序，

[wheatekzp]

c:\helloflask>pipenv shell
Launching subshell in virtual environment鈥?Microsoft Wind
版权所有 (c) 2009 Microsoft Corporation。保留所有权利。

(helloflask-_7dot6hq) c:\helloflask>cd demos\hello

(helloflask-_7dot6hq) c:\helloflask\demos\hello>flask run

之后就报错，如下：

• Environment: development

• Debug mode: on

• Restarting with stat
  Traceback (most recent call last):
  File "C:\ProgramData\Anaconda2\Lib\runpy.py", line 1

  "main", fname, loader, pkg_name)
  File "C:\ProgramData\Anaconda2\Lib\runpy.py", line 7
  exec code in run_globals
  File "C:\Users\Administrator.virtualenvs\helloflask
  e_main_.py", line 9, in
  File "c:\users\administrator.virtualenvs\helloflask
  s\flask\cli.py", line 894, in main
  cli.main(args=args, prog_name=name)
  File "c:\users\administrator.virtualenvs\helloflask
  s\flask\cli.py", line 557, in main
  return super(FlaskGroup, self).main(*args, **kwarg
  File "c:\users\administrator.virtualenvs\helloflask
  s\click\core.py", line 697, in main
  rv = self.invoke(ctx)
  File "c:\users\administrator.virtualenvs\helloflask
  s\click\core.py", line 1066, in invoke
  return process_result(sub_ctx.command.invoke(sub
  File "c:\users\administrator.virtualenvs\helloflask
  s\click\core.py", line 895, in invoke
  return ctx.invoke(self.callback, **ctx.params)
  File "c:\users\administrator.virtualenvs\helloflask
  s\click\core.py", line 535, in invoke
  return callback(*args, **kwargs)
  File "c:\users\administrator.virtualenvs\helloflask
  s\click\decorators.py", line 64, in new_func
  return ctx.invoke(f, obj, *args[1:], **kwargs)
  File "c:\users\administrator.virtualenvs\helloflask
  s\click\core.py", line 535, in invoke
  return callback(*args, **kwargs)
  File "c:\users\administrator.virtualenvs\helloflask
  s\flask\cli.py", line 771, in run_command
  threaded=with_threads, ssl_context=cert)
  File "c:\users\administrator.virtualenvs\helloflask
  s\werkzeug\serving.py", line 812, in run_simple
  reloader_type)
  File "c:\users\administrator.virtualenvs\helloflask
  s\werkzeug_reloader.py", line 275, in run_with_reload
  sys.exit(reloader.restart_with_reloader())
  File "c:\users\administrator.virtualenvs\helloflask
  s\werkzeug_reloader.py", line 132, in restart_with_re
  close_fds=False)
  File "C:\ProgramData\Anaconda2\Lib\subprocess.py", l
  return Popen(*popenargs, **kwargs).wait()
  File "C:\ProgramData\Anaconda2\Lib\subprocess.py", l
  errread, errwrite)
  File "C:\ProgramData\Anaconda2\Lib\subprocess.py", l

  startupinfo)
  TypeError: environment can only contain strings

有时候会报这个错误，如下：

(helloflask-_7dot6hq) c:\helloflask>cd demos\hell

(helloflask-_7dot6hq) c:\helloflask\demos\hello>fl
Usage: flask run [OPTIONS]

Error: Could not locate Flask application. You did
ironment variable.

For more information see http://flask.pocoo.org/do

折腾了几个小时，就是运行不了- -
python版本：Python 2.7.14 |Anaconda custom (64-bit)| (default, Mar 27 2018, 12:30:5
.1500 64 bit (AMD64)] on win32
Type "help", "copyright", "credits" or "license" for more information.
win7系统

[greyli]

第一个错误是因为0.14版本的Werkzeug在Windows下有一个bug，目前临时的解决方法是注释掉.flaskenv文件的FLASK_ENV定义那行：

FLASK_APP=sayhello
# FLASK_ENV=development

不过这会导致没法开启调试模式。替代的方法是修改 python-dotenv 源码，具体可以参考这里。
第二个错误描述不全，不太好判断。

[greyli]

先关闭了，有问题可以继续评论或重开。

[greyli]

python-dotenv 发布新版本了，使用下面的命令更新即可解决第一个问题：

$ pip install -U python-dotenv