Python简单基础小程序的实例代码

for i in range(9):#从0循环到8
  i += 1#等价于 i = i+1
  for j in range(i):#从0循环到i
    j += 1
    print(j,'*',i,'=',i*j,end = ' ',sep='')
    # end默认在结尾输出换行，将它改成空格 sep 默认 j,'*',i,'=',i*j 各元素输出中间会有空格
  print()#这里作用是输出换行符

i = 1
while i <= 9:
  j = 1
  while j <= i:
    print("%d*%d=%d" % (j,i,i*j),end=' ') # 格式化输出
    j += 1
  i += 1
  print()

user = 'hello world'
paswd = 123456
username = input("请输入用户名：")
password = input("请输入密码:")
for i in range(3):
  if username == user and int(password) == paswd: #判断用户名和密码是否都匹配
    print("欢迎您的到来")
    break
  elif i < 2:
    username = input("请输入用户名：")
    password = input("请输入密码")
  elif i == 2:
    print("账户已锁定")
    break

shop_car = []#用来存放购买的商品
goods = {
  1:['手机',2500],
  2:['电脑',3500],
  3:['自行车',4500],
  4:['宝马',20000]
}#商品列表
while True:
  salary = input("你有多少钱：") # 输入有多少钱
  if salary.isdigit(): # 判断是否为整数
    salary = int(salary) # 将字符串转化为整数
    print("是否要买东西：")
    flag1 = input("Y   N:")
    if flag1.upper() == 'N': # 将字符串大写
      exit("欢迎下次光临") # 退出程序并输出“欢迎下次光临”
    elif flag1.upper() == 'Y':
      break        # 终止循环
    elif flag1.upper() == 'Q':
      exit("欢迎下次光临")
  elif salary.upper() == 'Q':
    exit("欢迎下次光临")
while True:
    print("淘宝".center(30,'-')) # 输出以-----淘宝------
    for i in goods: # 循环输出
      print(i,goods[i])
    print("淘宝".center(30, '-'))
    choice_good = input("请输入商品编码：")#接受一个字符串
    if choice_good.isdigit() :
      choice_good = int(choice_good)
      if choice_good >= 1 and choice_good <= 4:
        if salary >= goods[choice_good][1]:
          shop_car.append(goods[choice_good][0]) # 给字典中添加元素
          salary = salary - goods[choice_good][1]
          print("您购买的商品为：", goods[choice_good][0])
          print("余额为：", salary)
          print("是否继续：")
          contin = input("Y  N")
          if contin.upper() == 'N':
            break
          elif contin.upper() == 'Q':
            break
        else:
          print('余额不足')
          print("是否继续：")
          contin = input("Y  N")
          if contin.upper() == 'N':
            break
          elif contin.upper() == 'Q':
            break
      else :
        print("没有这个编号")
        continue # 暂停本次循环
    elif choice_good.upper() == "Q" :
      break
    else:
      print("我看不懂。。。")
print("你买了：",end =' ')
for i in shop_car:
  print(i,end=' ')
print()
print("余额为：",salary)
print("欢迎下次光临")