Frequently Asked Questions

If you have a technial question not answered here, please post a question on StackOverflow:

  1. I work for a company interested in trying out the Tropofy Platform, can we evaluate it for free? - Access to the Tropofy Platform for evaluation purposes is free for all users. Simply email us at to request a developer key. Charges to access the Tropofy Platform only apply when you want to publish an app you have developed.
  2. I have a question, what is the best way to ask it? - Either contact us at or if it is technical in nature, please post it on StackOverflow:
  3. What operating systems does Tropofy run on? - Tropofy runs on all operating systems that support Python (which is pretty much all of them).
  4. I have an existing engine that runs on windows and is written in C#, can I create a Tropofy app to deliver this to my clients online? - Tropofy runs on all operating systems that support Python. So if you have an existing problem solving engine written in any language you can wrap it in a Tropofy app.
  5. What is the best way to call my problem solving engine from my Tropofy app if it is not written in Python? - There are many ways to call another programming language from Python. This page from the Python wiki is a great place to start. You can also use XML, CSV or some other form of file transfer.
  6. Can I use my own url? - Absolutely, simply run your Tropofy compute node on a computer wired to you url.
  7. Can you help me to configure my app? - Yes we can help you configure your app. We have done this for many customers, just contact us.
  8. Do I have to have example data in my app? - No you don’t, but it makes your app much more easy to understand if you provide example data.
  9. What browsers are Tropofy Apps compatible with? - Tropofy is compatible with all modern browsers: Chrome, IE10+, Mozilla Firefox, Opera
  10. Can I host my solver on my own machine and call it from with my Tropofy Compute node? - Absolutely, the batch geocoding worked example calls a webservice.
  11. Can I outsource the integration of my problem solving idea with the Tropofy framework to Tropofy? - Yes. We are happy to help integrate any existing code you may have that you want to integrate with a Tropofy app. Just contact us.
  12. If I have an idea, but do not know how to implement it, can I outsource both implementing my idea and its integration with the Tropofy Framework to Tropofy? - We have lots of experience in a variety of languages and operating systems, we would be only too happy to help.
  13. If I want to deploy an app for my business how much does it cost? - Following a successful evaluation and development of an app that you would like to publish, access to the Tropofy Platform is charged either on a per developer basis or site wide, depending on the level of technical support required, with an initial license fee and annual support. Hosting fees, if you elect to have Tropofy manage your compute nodes, are charged as a function of the maintenace effort and computing resources consumed.
  14. Do you support Python package XYZ? - Compute Nodes are responsible for running any calculations required, so you simply need to install the package on your compute node.
  15. I don’t like the default home page that Tropofy makes for my app, can I create my own? - Absolutely, just include the HTML code and javascript files for managing user sign up and login, by looking at the Tropofy page generated by default and include it in your own page as you see fit.
  16. I have confidential and sensitive information and IP that my app needs to run, that I must keep control of, how can I keep this safe? - The end user, the Tropofy Server and the Tropofy Compute nodes are all different physical machines. You can host your Tropofy compute nodes in house to ensure you have absolute control over any sensitive information.
  17. How are apps scaled using the Tropofy Platform? - The heavy lifting is done via the compute nodes. Spinning up as many compute nodes behind a load balancer base will ensure your app can take in the world! Amazon is great for handling this sort of thing.
  18. Why can’t others log into my app when I am developing it? - If you host a compute node and run an app using a development license key, only your developer’s login and password will work. When an app is published, the licensing changes and we talk to you about getting customers to log in.
  19. I am developing an App and I have changed some of my python classes which represent objects in the data base, and I am having database problems, what should I do? - When you are developing an app and using example data, the easiest thing to do is simply to delete the entire database. The database used for developing a Tropofy app is a SQLLite (but can be configured to point to any DB) file based databased in the same directory as your python files. Simply delete this file and the database will be recreated next time you run your app.
  20. Do I have to hand over any of my IP to Tropofy? - The terms of service state that your IP is yours and ours is ours. If you elect to have Tropofy host your app then yes we will have access to the server that hosts your IP. If you elect to manage your own compute nodes (Tropofy can help in this regard if needed) then your IP exists only on the compute nodes which you manage.
  21. What is a Python virtual environment and why does the install instructions make me create one? - A Virtual Environment, put simply, is an isolated working copy of Python which allows you to work on a specific project without worry of affecting other projects. It is an isolated sandbox into which you can install a bunch of python packages which will be ring fenced from your system installed packages and packages installed in other virtual environments. For example you can work on a project that requires a specific version of a package while still maintaining another project that requires an earlier version. For more info see here
  22. What editor should I use to build and debug my Tropofy App? - Anyone you like! At Tropofy we use PyCharm, Sublime Text, Visual Studio, pdb and even the command line. Use whichever one you like.
  23. Can I develop my Tropofy app offline? - Yes and no. Yes because a Tropofy app is defined by inheriting from classes in the Tropofy Framework, so you can write this Python code offline. No because, usually when developing people write a little bit of code and then see what effect it has, in order for you to run your app and test our your newly minted code, the machine you are developing on (which is acting as a compute node during development) needs to be able to connect to the Tropofy server for authentication.
  24. Can PuLP use more than one solver underneath? - Absolutely, that is the beauty of PuLP in addition to its fantastic model building syntax. At present you can swtich between COIN, GLPK, CPLEX and Gurobi using a one liner in Python
  25. I cannot seem to get Tropofy running after install! - Are you behind a proxy (meddlesome IT departments). See the section in our docs for dealing with this.