installed flask successfully, still getting import

I'm working with flask and python for the first time trying to create a web app. I'm on Windows 10 using Cygwin; for some reason, even though I've successfully installed flask using pip:

$ pip install flask
Requirement already satisfied (use --upgrade to upgrade): flask in c:\python34\l                                                                                                                ib\site-packages
Requirement already satisfied (use --upgrade to upgrade): click>=2.0 in c:\pytho                                                                                                                n34\lib\site-packages (from flask)
Requirement already satisfied (use --upgrade to upgrade): Jinja2>=2.4 in c:\pyth                                                                                                                on34\lib\site-packages (from flask)
Requirement already satisfied (use --upgrade to upgrade): itsdangerous>=0.21 in                                                                                                                 c:\python34\lib\site-packages (from flask)
Requirement already satisfied (use --upgrade to upgrade): Werkzeug>=0.7 in c:\py                                                                                                                thon34\lib\site-packages (from flask)
Requirement already satisfied (use --upgrade to upgrade): MarkupSafe>=0.23 in c:                                                                                                                \python34\lib\site-packages (from Jinja2>=2.4->flask)
You are using pip version 7.1.2, however version 9.0.1 is available.
You should consider upgrading via the 'python -m pip install --upgrade pip' comm                                                                                                             and.

I still get this error when running python app.py:

$ python app.py
Traceback (most recent call last):
  File "app.py", line 1, in <module>
    from flask import Flask
ImportError: No module named flask

any ideas? Sorry if this is a dumb question, pretty new at this.

回答1:

You need to create a virtualenv and then install pip in that.

virtualenv flasktest

next,

cd flasktest

then,

source bin/activate

lastly,

pip install flask

You should be all good with running flask (only in the virtualenv, it will not work outside of it.)

回答2:

Try this if you don't want to use virtualenv:

python -m pip install --upgrade pip
python -m pip install flask