利用字典的特性编写一个通讯录，记录姓名和联系(contact)电话
welcome = """
欢迎进入通讯录程序
1：查找联系人资料
2：插入新的联系人
3：删除联系人
4：退出程序
"""
print(welcome)
addressBook = {}
# with open('addressBook.txt', 'r+') as f:
# content = f.read()
# for eachline in content:
# (name, phone) = eachline.split(':')
# addressBook[name] = phone
while True: # 循环用来多次操作直到退出程序
n = int(input('请输入相应的选项：'))
if n == 1:
name = input("请输入要查找的联系人：")
if name in addressBook:
print(name + ':' + addressBook[name])
else:
print('查无此人！')
elif n == 2:
name = input("请输入新的联系人姓名：")
if name in addressBook:
print(name + '已经在通讯录里面')
else:
phone = input("请输入新的联系人的联系电话：")
addressBook[name] = phone
print(name + ':' + phone + '已添加')
elif n == 3:
name = input("请输入要删除的联系人：")
if not(name in addressBook):
print(name + '不在通讯录里面')
else:
del addressBook[name]
print(name + ':' + '已删除')
elif n == 4:
print('再见！')
break
