メモ「Automate the Boring stuff -chapter3 Functions」

#def Statements with Parameters
Deduplication makes your programs shorter, easier to read, and easier to update.

import random
 def getAnswer(answerNumber):
     if answerNumber == 1:
           return 'It is certain'
       elif answerNumber == 2:
           return 'It is decidedly so'
       elif answerNumber == 3:
           return 'Yes'
       elif answerNumber == 4:
           return 'Reply hazy try again'
       elif answerNumber == 5:
           return 'Ask again later'
       elif answerNumber == 6:
           return 'Concentrate and ask again'
       elif answerNumber == 7:
           return 'My reply is no'
       elif answerNumber == 8:
           return 'Outlook not so good'
       elif answerNumber == 9:
           return 'Very doubtful'

r = random.randint(1, 9)
fortune = getAnswer(r)
print(fortune)

Note that since you can pass return values as an argument to another function call, you could shorten these three lines:

r = random.randint(1, 9)
fortune = get answer(r)
print(fortune)

to this single equivalent line:

print(getAnswer(random.randint(1, 9)))

##The None Value

##Keyword Arguments and print()

#Local and Global Scope

I learned how local and global scope is different and could imagine how return function can be used.

A variable that exists in a local scope is called a local variable, while a variable that exists in the global scope is called a global variable.

Local Variables Cannot Be Used in the Global Scope

Local Scopes Cannot Use Variables in Other Local Scopes

Global Variables Can Be Read from a Local Scope

Local and Global Variables with the Same Name

The global Statement

#Exception Handling

#A Short Program: Guess the Number

# This is a guess the number game.
import random
secretNumber = random.randint(1, 20)
print('I am thinking of a number between 1 and 20.')

# Ask the player to guess 6 times.
for guessesTaken in range(1, 7):
    print('Take a guess.')
    guess = int(input())

    if guess < secretNumber:
        print('Your guess is too low.')
    elif guess > secretNumber:
        print('Your guess is too high.')
    else:
        break    # This condition is the correct guess!

if guess == secretNumber:
    print('Good job! You guessed my number in ' + str(guessesTaken) + ' guesses!')
else:
    print('Nope. The number I was thinking of was ' + str(secretNumber))

#Short Practice: the Collatz Sequence

'''
If number is even, then collatz() should print number // 2 and return this value.
If number is odd, then collatz() should print and return 3 * number + 1.
'''
def collatz(number):
    if number % 2 == 0:
        return number // 2
    elif number % 2 == 1:
        return 3 * number + 1
'''
Lets the user type in an integer and that keeps calling collatz() on that number 
until the function returns the value 1. 
'''
print('Enter number:')
try:
    info = int(input())
    while info != 1:
        info = collatz(info)
        print(info)
except ValueError:
    print('You must enter integer')