Python07 cycle

loop statement

• A Brief Discussion: Repeat thing
• Note: Set the stop cycling conditions, otherwise it will turn into an endless loop
• for ... in ... loop, indescribed in more iterables (e.g.: list, tuple, string, ...)
  • grammar: for 变量名 in list:

  • Example:

    list = [1,3,"Go",'Java','''Python''']
    for list_value in list:
        print(list_value)

  • operation result:
    
• range () function: generating a sequence of integer numbers of iterations may be

  • Example:

    # range() 函数
    rnumber1 = range(4) # 生成0-3之间(含 0，3)的数
    for i in rnumber1:
        print(i)
    number2 = range(1,3) # 生成 1-2 之间（含 1，2）的数
    for n in number2:
        print(n)

  • operation result:
    
• while loop: to meet the conditions will cycle
  • grammar: while 条件:

  • Example:

    var1 = 2
    while var1 > 0:
    print(var1)
    var1 -= 1  # 等同于 var1 = var - 1

  • operation result:
    
  • break、continue
    • break: out of the loop body

    • Example:

      # break : 跳出循环语句
        var2 = 10
        while var2 < 15:
            print(var2)
            var2 += 1
            if var2 == 12: # 如果var2 的值等于 12，执行break，跳出循环即结束循环
                break  

    • operation result:
      
  • continue: the end of the cycle, to enter the next cycle
    • Example:
      # continue 结束此次循环，进入下次循环 var3 = 1 while var3 < 10: var3 += 1 if var3 == 5:# 当var3 等于 5的时候，执行continue，跳出此次循环，即不执行打印var3，进入下次循环 continue print(var3)
    • operation result:
      
  • Infinite loop:
    • Example:
      while True: print("停不下来，哈哈哈")
    • Results: will always print停不下来，哈哈哈