Good understanding of how function calls work is especially important for understanding recursion. Stepping into a function call opens a new window with separate local variables table and code You can think of this light-blue box as a piece of paper where Python replaces subexpressions with their values, piece-by-piece.įaithful representation of function calls. If you use small steps, then you can even see how Python evaluates your expressions. Steps follow program structure, not just code lines. Press F6 for a big step and F7 for a small step. Just press Ctrl+F5 instead of F5 and you can run your programs step-by-step, no breakpoints needed. Once you're done with hello-worlds, select View → Variables and see how your programs and shell commands affect Python variables. (You can also use a separate Python installation, if necessary.) The initial user interface is stripped of all features that may distract beginners. Thonny comes with Python 3.7 built in, so just one simple installer is needed and you're ready to learn programming.