Python — the basics

Python is the language almost all AI code is written in. It reads almost like pseudocode:

score = 12
if score > 10:
    print("Pass")
else:
    print("Try again")

Indentation (four spaces) is not ornament — it decides what belongs to the if.

A function packages code so it can be reused:

def vat(price):
    return price * 0.25

print(vat(200))   # 50.0

Error messages are read from the bottom up. NameError: name 'price' is not defined means you have used a name that does not exist — often a typo, or the variable is created later in the code. TypeError means you have mixed kinds, for instance text + number.

The types you need first: int (whole numbers), float (decimals), str (text), bool (True/False). type(x) shows the type. int("12") turns text into a number; str(12) does the opposite. input() always gives a str — do not forget to convert.