5-2

str = 'Hello'
if str == 'Hello':
    print('str = Hello')
    
if str != '123':
    print('str != 123')

if str.lower() == 'hello':
    print('str.lower() = hello')

if(1 == 2-1):
    print('1==1')

if 1!=2:
    print('1!=2')

if 1<2:
    print('1<2')

if 2>1:
    print('2>1')

if 2>=1:
    print('2>=1')

if 1<=2:
    print('1<=2')
    
if 1<2 and 2<3:
    print('1<2<3')

if 1<2 or False:
    print('1<2')

numbers = range(1,10)
if 10 not in numbers:
    print('10 not in range(1,10)')
if 3 in range(1,10):
    print('3 in range(1,10)')
 

5-7

favorite_fruits = ['apple','pear','grape']

if 'apple' in favorite_fruits:
    print('You really like bananas!')
if 'pear' in favorite_fruits:
    print('You really like bananas!')    
if 'grape' in favorite_fruits:
    print('You really like bananas!')
if 'banana' in favorite_fruits:
    print('You really like bananas!')
if 'watermelon' in favorite_fruits:
    print('You really like bananas!')
 

5-11

for i in range(1,10):
    flag = 'th'
    if i==1:
        flag = 'st'
    elif i==2:
        flag = 'nd'
    elif i==3:
        flag = 'rd'
    print(str(i)+flag)

5-12：5-11的稽核後的程式碼

for i in range(1,10):
    flag = 'th'
    if i == 1:
        flag = 'st'
    elif i == 2:
        flag = 'nd'
    elif i == 3:
        flag = 'rd'
    print(str(i) + flag)