2018年6月28日

users = ['jason', 'tom', 'mike', 'yangling', 'admin']
for user in users:
    if user == 'admin':
        print("Hello {},would you like to see a status report?".format(user))
    else:
        print("Hello {},thank you for logging in again".format(user))

Hello jason,thank you for logging in again
Hello tom,thank you for logging in again
Hello mike,thank you for logging in again
Hello yangling,thank you for logging in again
Hello admin,would you like to see a status report?

users = ['jason', 'tom', 'mike', 'yangling', 'admin']
if users == []:
    print("We need to find some users!")
else:
    for user in users:
        if user == 'admin':
            print("Hello {},would you like to see a status report?".format(user))
        else:
            print("Hello {},thank you for logging in again".format(user))
            

Hello jason,thank you for logging in again
Hello tom,thank you for logging in again
Hello mike,thank you for logging in again
Hello yangling,thank you for logging in again
Hello admin,would you like to see a status report?

for i in range(1, 10):
    if i == 1:
        print("1st")
    elif i == 2:
        print("2nd")
    elif i == 3:
        print("3rd")
    else:
        print("{}th".format(i))

1st
2nd
3rd
4th
5th
6th
7th
8th
9th

current_users = ['jason', 'Tom', 'jone', 'John', 'bob']
current_users_lower = [user.lower() for user in current_users]
new_users = ['jason', 'JOHN', 'mary', 'lily', 'jack']
for user in new_users:
    if user.lower() in current_users_lower:
        print("{} already exists.".format(user))
    else:
        print("{} is avaliable.".format(user))

jason already exists.
JOHN already exists.
mary is avaliable.
lily is avaliable.
jack is avaliable.

person = {'first_name': 'zhang', 'last_name': 'bo', 'age': 38, 'city': 'wuxi'}
print(person)
print(person['first_name'])

{'first_name': 'zhang', 'last_name': 'bo', 'age': 38, 'city': 'wuxi'}
zhang

person = {'first_name': 'zhang', 'last_name': 'bo', 'age': 38, 'city': 'wuxi'}
for k, v in person.items():
    print("{}:{}".format(k,v))
    

first_name:zhang
last_name:bo
age:38
city:wuxi