Python 作业

• 设计"过7游戏"的程序，打印出1-100之间除了含7和7的倍数之外的所有数字

  i = 0
  while i <= 99:
      i += 1
      if i % 7 == 0:
          continue
      elif i - i // 10 * 10 == 7:
          continue
      elif i//10 == 7:
          continue
      print(i, end=" ")
      
  1 2 3 4 5 6 8 9 10 11 12 13 15 16 18 19 20 22 23 24 25 26 29 30 31 32 33 34 36 38 39 40 41 43 44 45 46 48 50 51 52 53 54 55 58 59 60 61 62 64 65 66 68 69 80 81 82 83 85 86 88 89 90 92 93 94 95 96 99 100 
  

• 编写程序用户登录程序仅有三次机会。（if和for)

  flag = 0
  for i in range(3):
      username = input('请输入用户名：')
      password = input('请输入密码：')
      if username == '123' and password == '456':
          flag = 1
          print('登录成功！')
          break
  if flag == 0:
      print('三次输入错误，退出程序')
      
      
  请输入用户名：123
  请输入密码：456
  登录成功！
  

• 编写程序实现，判断一串字符串是否为有效变量名

  import string
  flag = 0
  str = input("请输入变量名:")
  a = string.ascii_letters
  b = string.digits
  if str[0] in a or str[0] == '_':
      for i in str[1:]:
          if i not in a and i not in b and i !='_':
              flag = 1
  
      if flag == 1:
          print("变量名错误")
      else:
          print("变量名正确")
  else:
      print("变量名错误")
  

• 最多猜10次数字的游戏，猜测范围1～100，根据input内容提示猜大或者猜小，如果猜中，结束循环

  a = 58
  for i in range(10):
      num = int(input("请输入1-100中一个数："))
      if num >= 1 and num <= 100:
          if num > a:
              print("偏大")
          elif num < a:
              print("偏小")
          else:
              print("猜中")
              break
      else:
          print("请输入正确范围的数")
  

• 使用while循环实现输出2-3+4-5+6…+100的和

  i = 1
  a = 1
  sum = 0
  while i <= 100:
      sum += i * a
      i += 1
      a = -a
  print(sum)
  
  
  -50
  

• 使用循环实现九九乘法表

  i = 1
  j = 1
  for i in range(1, 10):
      for j in range(1, i + 1):
          print(i, '*', j, '=', i * j, end=" ")
      print('')
      
  1 * 1 = 1 
  2 * 1 = 2 2 * 2 = 4 
  3 * 1 = 3 3 * 2 = 6 3 * 3 = 9 
  4 * 1 = 4 4 * 2 = 8 4 * 3 = 12 4 * 4 = 16 
  5 * 1 = 5 5 * 2 = 10 5 * 3 = 15 5 * 4 = 20 5 * 5 = 25 
  6 * 1 = 6 6 * 2 = 12 6 * 3 = 18 6 * 4 = 24 6 * 5 = 30 6 * 6 = 36 
  7 * 1 = 7 7 * 2 = 14 7 * 3 = 21 7 * 4 = 28 7 * 5 = 35 7 * 6 = 42 7 * 7 = 49 
  8 * 1 = 8 8 * 2 = 16 8 * 3 = 24 8 * 4 = 32 8 * 5 = 40 8 * 6 = 48 8 * 7 = 56 8 * 8 = 64 
  9 * 1 = 9 9 * 2 = 18 9 * 3 = 27 9 * 4 = 36 9 * 5 = 45 9 * 6 = 54 9 * 7 = 63 9 * 8 = 72 9 * 9 = 81 
  
  

• 已知列表list=[22478,24066,23398,38498],利用字符串拼接及遍历，输出结果"城市学院"

a = ""
li = [22478, 24066, 23398, 38498]
for i in range(4):
    a += chr(li[i])
print(a)

城市学院