A · SetupBeginner50 min read
3. Syntax, types & control flow
Python · 52 pages source format
Indentation, variables, strings, f-strings, if/for, lists, dicts. Enough to read test code and write helpers.
What you'll learn
- Indentation rules
- f-strings
- if/elif/else
- for loops
- lists and dicts
Variables and f-strings
Dynamic typing — types exist at runtime. f-strings are the readable default for formatting.
username = "standard_user"
password = "secret_sauce"
print(f"Attempting login for {username}")Do this now
Script that stores username/password and prints formatted login attempt.
Clear?
Control flow
if/elif/else for branching. for item in items for iteration. while sparingly.
Do this now
Loop over 3 invalid passwords; print whether each is empty or too short.
Clear?
Lists and dicts
Lists ordered, dicts keyed. List comprehensions when readable. dict.get(key, default) avoids KeyError.
admins = [u["name"] for u in users if u.get("role") == "admin"]Do this now
users = [{"name":"A","role":"admin"},{"name":"B","role":"user"}]. Filter admins, print names.
Clear?