If I am able to program in Python but not C or C++, what are my career options?
The short and obvious answer: learn C++! C++ is a strictly typed language and there are situations where this is the right choice. No one programming language is going to be right for ALL situations. C and C++ provide a solid foundation in software development. C++'s strict typing can be a powerful tool to have in your toolbox.
Don't get me wrong, I love Python. For many, many use cases it's a decent choice. In my opinion programmers should know and understand C/C++ even if they don't "need" them for their current projects. I think that learning a strictly typed language along with a "duck typing" language like Python helps you understand software development at a deeper level. You will be better positioned to learn other languages as needed and you will understand the pros and cons of each type of language.
I would be somewhat skeptical of a programmer who had NO experience with C++. They have an uphill battle convincing me that had a solid grasp of software development. I've seen many languages come and go but C/C++ remain standing proud.
To your question, a couple of areas I've seen Python used frequently:
Manufacturing test code: this is code written to run at the manufacturing facility (or contract manufacturer) for hardware products (such as IoT, networking equipment, consumer electronics, robotics). That said, there is often snippets of code that has to be in C or even assembly to test lower level components of the system.
DevOps scripting tools: Python is a great enhancement over shell scripting or PERL IMO. Automation for deployments, continuous integration/continuous deployment.
Data Scientists: They use R and Python with NumPy and related modules.
Backend/server systems: With Django and other tools you can build websites. With build in modules or open source enhancements you can build web services.
Machine learning: both for machine learning itself and for developing the tools needed to establish the ground truth...
Tinkering and basic IoT: Raspberry Pi has Python as do most other development boards.
This guy's blog says many of the same things regarding common Python use cases: Python Application Development: Common Use Cases and Project Examples
A couple of years back and you would have been in trouble a little.
In 2018, you are in luck my friend cuz i have good news for you. In the modern era there is a massive need of the upcoming tech known as Artificial Intelligence (A.I). Well this AI called thing is all about Machine Learning techniques, and that totally deapnds on your skills in Python!
Python is the language that is easy, quick and reliable. Used by many industries as of today and it's not going anywhere to nothing in coming decade or so...
What I would tell you is that go for Machine learning.