matraz instalado con éxito, todavía obteniendo error de importación

Estoy trabajando con frasco y python por primera vez tratando de crear una aplicación web. Estoy en Windows 10 usando Cygwin; por alguna razón, a pesar de que instalé con éxito el matraz usando 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.

Todavía recibo este error cuando ejecuto 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

¿algunas ideas? Lo siento si esta es una pregunta tonta, bastante nueva en esto.

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