Python——if条件、while循环、for循环语句

（1）#if 语句 验证用户名和密码user = 'Zhaoxiaoxue'

password = '123456'
username = ''
passnumber = ''
while user != username or password != passnumber :
    username = input("Please enter username: ")
    passnumber = input("Please enter password: ")
    if user == username and password == passnumber :
        print('Welcome,%s!' % username)
        break
    else :
        print("username or password is invalid!")

（2）#while、for循环

'''
#while 循环顺序输出0~99  验证break
count=0
while True:
    print("count: ",count)
    count+=1
    if count==100:
        break

'''

'''
#for循环 验证continue
for i in range(0,10):
    if i<5 :
        print('loop ',i)
    elif i==5 :
        print("loop :",i)
    else :
        continue
    print("hello!")
    
'''
#嵌套for循环
for i in range(1,11) :
    print ("*********",i)
    for j in range(10) :
        print (j)
        if j==4 :
            break