Dragon Realm - Invent Your Own Computer Games with Python - page 72

Deciding Which Cave has the Friendly Dragon
28. friendlyCave = random.randint(1, 2)
Now we are going to have the program randomly chose which cave had the friendly
dragon in it. Our call to the random.randint() function will return either the integer 1
or the integer 2 , and store this value in a variable called friendlyCave .
30. if chosenCave == str(friendlyCave):
31. print('Gives you his treasure!')
Here we check if the integer of the cave we chose ( '1' or '2' ) is equal to the cave
randomly selected to have the friendly dragon. But wait, the value in chosenCave was a
string (because input() returns strings) and the value in friendlyCave is an integer
(because random.randint() returns integers). We can't compare strings and integers
with the == sign, because they will always be different ( '1' does not equal 1 ).
Comparing values of different data types with the == operator will always evaluate to
False .
So we are passing friendlyCave to the str() function, which returns the string
value of friendlyCave.
What the condition in this if statement is really comparing is the string in
chosenCave and the string returned by the str() function. We could have also had this
line instead:
if int(chosenCave) == friendlyCave:
Then the if statement's condition would compare the integer value returned by the int
() function to the integer value in friendlyCave . The return value of the int()
function is the integer form of the string stored in chosenCave .
If the if statement's condition evaluates to True , we tell the player they have won the
treasure.
32. else:
33. print('Gobbles you down in one bite!')
Line 32 has a new keyword. The else keyword always comes after the if-block. The
else-block that follows the else keyword executes if the condition in the if statement was