Conclusion

This chapter made Python programs less linear.

Branches choose what code runs. Loops repeat code. Conditions and comparisons produce the booleans that branches and while loops use. for loops repeat over known sequences. Running totals accumulate evidence across repeated steps. Off-by-one checks keep boundaries honest.

The important habits are:

• read conditions as booleans
• check if, elif, and else from top to bottom
• use indentation to see the block
• use for when iterating over a known sequence
• use while when the stopping condition is the main idea
• initialize totals before the loop
• print boundaries when a range feels uncertain

What Comes Next

The next chapter introduces functions. A function lets you name a reusable piece of computation. Many loops become clearer once the repeated work is placed inside a function.

Before moving on, make sure you can predict a short branch and trace a short loop without running it first.