Solved with Python 2.7.10

Installation

pip2 install -r requirements.txt (for pytest and argparser)

Usage

python2 app.py -file {path to file}

Example (included):

python2 app.py -file test/test_file.txt

Testing

pytest test

Assumptions:

• We assume we will always be given a valid prefix expression:

  "You are given a prefix expression".

• We assume only a small subset of possible operators will be used: *, / and +