I don't know if you already did this, but to work with GAE and python you need have the dependent packages inside your project, as Flask, Werkzeug, Jinja2 and SimpleJson.
Here there is the script I use on my project:
# set the path of your project
PATH_PROJECT=~/Development/python/projects/scheduler-i-sweated-yesterday
cd ~/Downloads
#
# Installing Flask: https://github.com/mitsuhiko/flask/tags
#
wget https://github.com/mitsuhiko/flask/archive/0.9.zip
unzip 0.9.zip
mv flask-0.9/flask $PATH_PROJECT/flask
#
# Installing Werkzeug: https://github.com/mitsuhiko/werkzeug/tags
#
wget https://github.com/mitsuhiko/werkzeug/archive/0.8.3.zip
unzip 0.8.3.zip
mv werkzeug-0.8.3/werkzeug $PATH_PROJECT/werkzeug
#
# Installing Jinja2: https://github.com/mitsuhiko/jinja2/tags
#
wget https://github.com/mitsuhiko/jinja2/archive/2.6.zip
unzip 2.6.zip
mv jinja2-2.6/jinja2 $PATH_PROJECT/jinja2
#
# Installing SimpleJson: https://github.com/simplejson/simplejson/tags
#
wget https://github.com/simplejson/simplejson/archive/v3.0.5.zip
unzip v3.0.5.zip
mv simplejson-3.0.5/simplejson $PATH_PROJECT/simplejson
Save as install_packages_dependencies.sh and after that run in the shell:
bash install_packages_dependencies.sh