python代码实现图书管理系统

#-*- coding=utf8 -*- 
# @author:sololi
# date: 2020/11/12
# 文件说明 : data
import sys
def print_muen():
 print("----菜单提示----")
 print("[1]:添加图书")
 print("[2]:查询图书")
 print("[3]:删除图书")
 print("[4]:修改图书信息")
 print("[5]:显示所有图书")
 print("[6]:退出")

def add_book():
 book_id=input("请输入图书编号")
 book_name=input("请输入图书名称")
 book_loc=input("请输入图书位置")
 for i in books:
 if book_id==i["book_id"]:
 print("编号重复")
 break
 else:
 book={}
 book["book_id"]=book_id
 book["book_name"]=book_name
 book["book_loc"]=book_loc
 books.append(book)
 new_file(books)
 print("添加成功")

def find_book():
 jg=0
 while True:
 book_name=input("输入要找的书名")
 for i in books:
 if book_name==i["book_name"]:
 print(i)
 jg=1
 if jg==0:
 print("查找失败请重新输入")
 continue
 elif jg==1:
 break

def dell_book():
 book_name =input("请输入图书书名")
 i=0
 j=0
 jg=0
 flag=[]
 while i<len(books):
 if books[i]["book_name"]==book_name:
 id=books[i]["book_id"]
 flag.append(id)
 print("图书编号:{}".format(id))
 jg=1
 i+=1
 if jg==0:
 print("找不到图书名")
 if jg==1:
 book_id=input("请输入删除的图书编号")
 i=0
 while j < len(flag):
 if flag[j] == book_id:
 while i < len(books):
  if books[i]["book_id"] == book_id:
  del books[i]
  new_file(books)
  print("删除成功")
  break
  i+=1
 break
 j+=1
 else:
 print("输入的编号有误")
 return books

def modify_book():
 book_name = input("请输入修改的图书名称")
 i = 0
 jg = 0
 flag = []
 while i < len(books):
 if books[i]["book_name"] == book_name:
 id = books[i]["book_id"]
 flag.append(id)
 print("本书图书编号:{}".format(id))
 jg = 1
 i += 1
 if jg == 0:
 print("找不到图书名")
 elif jg == 1:
 book_id = input("请输入修改的图书编号，或者其他需要修改的图书编号")
 for i in books:
 if book_id == i["book_id"]:
 New_id = input("新的图书编号")
 if New_id == i["book_id"]:
  print("输入编号重复")
  break
 else:
  New_name = input("新的图书名称")
  New_loc = input("新的图书位置")
  i["book_id"] = New_id
  i["book_name"] = New_name
  i["book_loc"] = New_loc
  new_file(books)
  break
 else:
 print("输入有误")

def all_book():
 for i in books:
 print(i)

def read_book(data):#将文本文件里的图书信息读取到books中
 f = open(data, mode="r", encoding="utf8")
 books = f.readlines()
 f.close()
 for i in range(0, len(books)):
 books[i] = eval(books[i].replace("\n", ""))
 return books

def new_file(books):#将books的内容更新到文本文件里
 i=0
 nf = open('data', 'w+',encoding='utf8') # 以清空原文本文件内容的方式打开文件写入
 while i<len(books):
 new=str(books[i])
 nf.write(new)
 if i !=len(books)-1:
 nf.write("\n")
 i+=1
 nf.close()

if __name__=="__main__":#主要流程
 while True:
 data="data"
 books=read_book(data)
 print_muen()
 choice=input("请输入您的选择")
 if choice=='1':
 add_book()
 all_book()
 elif choice=='2':
 find_book()
 elif choice=='3':
 dell_book()
 all_book()
 elif choice=='4':
 modify_book()
 all_book()
 elif choice == '5':
 all_book()
 elif choice == '6':
 print("感谢您的使用")
 sys.exit(0)
 else:
 print("您的输入有误,请重新输入")