Control Flow：程式執行順序

if statement (如果…則…)

1. 用簡單判斷做決策時使用。例：票價分類，小於等於8歲免費，大於8歲300元
2. 如果(A)符合，則做(B事)，否，則做(C事)。
3. 判斷裡可以放置內容，並回傳布林值：
   1. Comparison Operator ( ==, ! =, >, <, > =, < =)
   2. Logical Operator (and, or, not)
   3. True or False

# age < 8 , ticket free
# age >= 8 and age < 65, ticket 300
# age > 65, ticket 150

age = 28

if age < 8:
    print("Your age is " + str(age) + ", movie is free for you !!")
elif 8 <= age < 65:
    print("Your age is " + str(age) + ", you need to pay $300.")
else:
    print("Your age is " + str(age) + ", you need to pay $150.")

“for” loop (依據Ａ，執行B)

1. 使用在iterable object(循環物件)，例：list, tuple, set, string等
2. 最長搭配range()使用：for i in range(a, b, c)

#for variable in interble:
#   do something here

for letter in "Hello World":
    if letter == letter.upper():
        print(letter)