内置函数练习
编写 sql 查询语句功能
文件内容：
1,Eva,22,13651054608,IT
2,Vera,23,13304320533,Tearcher
3,Renault,25,1333235322,IT
实现：
装饰器登录
select name, age where age>22
select * where age>22
select * where phone like 133
select * where occ=IT（字符串比较未实现，与年龄的数字比较有冲突 待解决）
#读文件
def dir():
with open('d:/py/info.txt',encoding='utf-8')as f:
for line in f:
line = line.strip().split(',')
yield line d =dir() #实现显示
def view(option,lis):
dic = {'id':lis[0],'name':lis[1],'age':lis[2],'phone':lis[3],'occ':lis[4]}
option = option.split().pop(1).split(',')
for i in option:
if i in dic:
print(dic[i],end=' ')
elif i == '*':
print(lis)
else:
print('输入字段有误') # sel 判断
def judge(option,condition):
if '>' in condition:
a,b = condition.split('>')
for lis in dir():
if int(d.__next__()[2]) > int(b):
view(option,lis)
elif '<' in condition:
a,b = condition.split('<')
for lis in dir():
if int(d.__next__()[2]) < int(b):
view(option,lis)
elif '=' in condition:
a,b = condition.split('=')
for lis in dir():
if int(d.__next__()[2]) == int(b):
view(option,lis) #实现 like 查找功能
def like(s):
if 'like' in s and '*' in s:
val,con = s.split('like')
val = val.split().pop().strip()
con = con.strip()
for lis in dir():
if con in d.__next__()[3]:
print(lis) #实现登录
def login(f):
def inner():
use = input('账号 >>>')
pwd = input('密码 >>>')
if use == 'ysg' and pwd == '':
ret = f()
return ret
else:
print('登录失败')
return inner #实现 select（主函数）
@login
def sel():
s = input('输入语句 >>>')
#s = 'select name,age where age>22'
option,condition = s.split('where')
condition = condition.strip()
#strs(s) #实现字符串比较的功能
like(s) #实现 like 查找功能
judge(option,condition) #实现数字比较的功能 sel()
面试题：阅读代码，说出输出结果
def extendList(val,list=[]):
list.append(val)
return list
list = extendList(10)
list2 = extendList(123,[])
list3 = extendList('a') print("list = %s"%list)
print("list2 = %s"%list2)
print("list3 = %s"%list3) #结果
list = [10, 'a']
list2 = [123]
list3 = [10, 'a']