作业要求：下述所有代码画图以及分析代码执行流程
1、以定义阶段为准，先画出名称空间的嵌套关系图
2、然后找到调用函数的位置，写出函数调用时代码的执行过程，涉及到名字的查找时，参照1中画好
的嵌套图，标明查找顺序，一层一层直到找到位置
===================题目一===================
input=333
def func():
input=444
func()
print(input)
===================题目二===================
def func():
print(x)
x=111
func()
===================题目三===================
x=1
def func():
print(x)
def foo():
x=222
func()
foo()
===================题目四===================
input=111
def f1():
def f2():
# input=333
print(input)
input=222
f2()
f1()
===================题目五===================
x=111
def func():
print(x) #
x=222
func()
===================题目六===================
x=111
def foo():
print(x,)
def bar():
print(x)
foo()
bar()
===================题目七===================
x=1
def func2():
func1()
x=2
def func1():
print(x)
x=3
func2()
===================题目八===================
1、如下全局变量记录了当前登录用户，编写登录功能，一旦用户登录成功，则将全局变量赋值为当前登录的用户名
login_user=None
login_user=None
def login():
username=input('用户名：')
password=input('密码：')
with open('logn.txt',mode='rt',encoding='utf-8') as f:
for line in f:
user,pwd=line.strip().split(':')
if username==user and password==pwd:
login_user = username
print(login_user,'登陆成功')
return
else:
print('登陆失败')
login()
2、针对之前编写的查询余额的功能，添加额外的逻辑：如果用户没有登录，则先执行登录功能
def check_money(username):
dic = {}
with open('a.txt', 'r', encoding='utf-8') as f:
for line in f:
user, money = line.strip().split(':')
dic[user] = float(money)
if not user_info.get('user'):
login()
if username not in dic:
return
return dic.get(username)
