Question

我通过pip3安装了flask之后，为什么不能运行它？那我该如何运行呢？谢谢。

$ pip3 install Flask
Collecting Flask
  Using cached https://files.pythonhosted.org/packages/7f/e7/08578774ed4536d3242b14dacb4696386634607af824ea997202cd0edb4b/Flask-1.0.2-py2.py3-none-any.whl
Collecting Werkzeug>=0.14 (from Flask)
  Using cached https://files.pythonhosted.org/packages/20/c4/12e3e56473e52375aa29c4764e70d1b8f3efa6682bef8d0aae04fe335243/Werkzeug-0.14.1-py2.py3-none-any.whl
Collecting click>=5.1 (from Flask)
  Using cached https://files.pythonhosted.org/packages/fa/37/45185cb5abbc30d7257104c434fe0b07e5a195a6847506c074527aa599ec/Click-7.0-py2.py3-none-any.whl
Collecting Jinja2>=2.10 (from Flask)
  Using cached https://files.pythonhosted.org/packages/7f/ff/ae64bacdfc95f27a016a7bed8e8686763ba4d277a78ca76f32659220a731/Jinja2-2.10-py2.py3-none-any.whl
Collecting itsdangerous>=0.24 (from Flask)
  Using cached https://files.pythonhosted.org/packages/76/ae/44b03b253d6fade317f32c24d100b3b35c2239807046a4c953c7b89fa49e/itsdangerous-1.1.0-py2.py3-none-any.whl
Collecting MarkupSafe>=0.23 (from Jinja2>=2.10->Flask)
  Using cached https://files.pythonhosted.org/packages/08/04/f2191b50fb7f0712f03f064b71d8b4605190f2178ba02e975a87f7b89a0d/MarkupSafe-1.1.0-cp36-cp36m-manylinux1_x86_64.whl
Installing collected packages: Werkzeug, click, MarkupSafe, Jinja2, itsdangerous, Flask
Successfully installed Flask-1.0.2 Jinja2-2.10 MarkupSafe-1.1.0 Werkzeug-0.14.1 click-7.0 itsdangerous-1.1.0

$ export FLASK_APP=hello.py

$ python3 flask run
python3: can't open file 'flask': [Errno 2] No such file or directory

Answer 1

尝试作为模块

python -m flask运行

Answer 2

您的命令无法运行，因为python3需要一个文件作为其参数，并且那里没有文件（或目录，请查看下面链接的文档）。

选项-m module-name将在sys.path中搜索您传递的模块，并将其内容作为__main__模块执行。查看官方docs。

您可能已经看到一个例子，人们运行python3 -m http.server来从当前目录中提供文件。

通过pip3安装flask之后，为什么不能运行它？

2 个答案: