Control Flow

if / else / elif, for and while loops, and Python's gentle error-handling — try/except.

Foundations 6 lessons ~50 min

Lessons in this module

1. if / else — making decisions · 8 min
   Python's IF() statement: indentation, elif, the comparison operators in action.
2. for loops — doing something for every item · 9 min
   Loop through lists, ranges, dictionaries, and lines of a file.
3. while loops — repeat until done · 6 min
   When you don't know how many iterations you need: while, break, and the infinite-loop pitfall.
4. List comprehensions — one-line loops · 7 min
   The compact way to build a list from another list. Less code, more clarity.
5. try / except — handling errors gracefully · 7 min
   Catch exceptions so your script keeps running instead of dying on bad data.
6. Putting it together — a mini contact-cleaner · 8 min
   Combine if/for/comprehensions/try-except into your first useful script.