排序,其他的运用 os fork

while True:
    str_num = input("Enter number:")

    flag = True
    dotCount = 0
    if str_num[0] == '-':
        str_num_copy = str_num[1:]
    else:
        str_num_copy = str_num
    for ch in str_num_copy:
        if ch>='0' and ch <= '9':
            continue
        elif ch == '.':
            dotCount += 1
            if dotCount>1:
                flag = False
                print("您输入的内容不规范,请重新输入")
                break
            continue
        else:
            flag = False
            print("您输入的内容不规范,请重新输入")
            break
    if flag == True:
        print(float(str_num))
        break

# import math
# while True:
#     x = input('Enter number:')
#     y = int(x) / 6
#     num = math.ceil(y)
#     print(num)
# # 用列表解析的方式
# while True:
#     x = input('Enter number:')
#     num = int(x)
#     page = num // 6
#     n = 1 if num%6!=0 else 0
#     print(page+n)


#排序
# list1 = [5,4,3,2,1,2,3,4,5]
# #对list1进行排序 排序之后改变了id号
# l = sorted(list1)#result:[1, 2, 2, 3, 3, 4, 4, 5, 5]
# print(l)#[1, 2, 2, 3, 3, 4, 4, 5, 5]
# print(id(l),id(list1))#43557960 43558536
#
# list1 = [5,4,3,2,1,2,3,4,5]
# #对list1进行排序 排序之后改变了id号
# l = list1.sort()
# print(l,list1)# None [1, 2, 2, 3, 3, 4, 4, 5, 5]
# print(id(l),id(list1))#1790284944 43688648
#
# list1 = [5,4,3,2,1,2,3,4,5]
# print(id(list1))#43689032
# #对list1进行排序 排序之后不改变id号
# list1.sort()
# print(list1)#[1, 2, 2, 3, 3, 4, 4, 5, 5]
# print(id(list1))#43689032

import os
#fork不支持windows上面运行
if __name__ == '__main__':
    pid = os.fork()
    print(pid)