Python is one of the most popular languages in the world. It's widely used in Web development, data science and machine learning, devops, and automated testing. Stack Overflow reports that it's not only the most popular language on their site, but also the fastest growing language.
So Python is popular. And it's only getting more popular over time.
Bottom line: If you know Python, then you can get a great job. Or you can keep your current job, and improve your standing (and thus your salary).
I know this, because some of the world's best-known companies invite me to teach Python to their engineers. Just about every day, I go to companies like Apple, Cisco, Ericsson, IBM, Intel, and VMWare, teaching Python to their staff. These companies are always looking for people who know Python — but because such people are hard to find, they bring me in to train their existing developers.
My students are typically experienced with C, C++, C#, and Java. So they know how to program, but they don't know Python. I sometimes say that they can program in Python, but with a Java accent — meaning, they might know how to get things done, but not in the most efficient or "Pythonic" way.
My intro course covers data structures, working with files, writing and calling functions, basic functional programming, modules, and basic object-oriented programming. Throughout the course, I give my students exercises that force them to use what they've learned, and to integrate these ideas into their Python coding. By the end of the course, they're ready to use Python to solve problems, and to do their jobs — not just because they know Python, but because they have a sense of how it works, and how to teach themselves more.
My course begins with a tour through Python's syntax and data structures — strings, lists, tuples, and dictionaries. These are the data structures that you must master if you'll become fluent in Python. Lists, tuples, and dicts aren't just for beginner Python developers; the language itself is implemented using oodles of lists, tuples, and dicts. And the sooner you know how to work with them, the sooner you'll become fluent in Python.
This course will eventually (by January 2019) contain 7-8 hours of video lessons, although with many hands-on exercises. I've currently recorded about 3 hours of video lessons, meaning that updates and additions will be coming very soon.
If you're an experienced developer who has always wanted to learn Python, this is the best starting point I can think of. I've given this course hundreds of times, to thousands of developers around the world. I've honed my explanations and exercises to ensure that you'll have the optimum learning experience.