python 基础习题

时间:2021-02-06 18:14:19

1、8<<2等于?

8  ---> 1000
32 ---> 100000
-----------结果---
32

2、通过内置函数计算5除以2的余数

print(dir())    #不带参数时,返回当前范围内的变量、方法和定义的类型列表,#找到__builtins__
print(dir(__builtins__)) #找内置函数 print(divmod(5,2)[1])
----------------------结果-----------
1 

3、s=[1,"h",2,"e",[1,2,3],"l",(4,5),"l",{1:"111"},"o"],将s中的5个字符提取出来并拼接成字符串。

方法一:

s1 = []
for n in s:
if type(n) == str:
s1.append(n)
print("".join(s1)) 方法二: print("".join([i for i in s if type(i) == str]))

4、判断"yuan"是否在[123,(1,"yuan"),{"yuan":"handsome"},"yuanhao"],如何判断以及对应结果?

s1 = [123,(1,"yuan"),{"yuan":"handsome"},"yuanhao"]

def foo(name):
if "yuan" in name:
print(name)
for i in name:
if type(i) == list or type(i) == tuple:
foo(i)
if type(i) == dict:
foo(i.keys())
foo(i.values()) foo(s1) -----------结果为---------
(1, 'yuan')
dict_keys(['yuan'])

6、 a=[1,2,[3,"hello"],{"egon":"aigan"}]
b=a[:]

a[0]=5
a[2][0]=666

print(a)
print(b)
#计算结果以及为什么?

[5, 2, [666, 'hello'], {'egon': 'aigan'}]
[1, 2, [666, 'hello'], {'egon': 'aigan'}] b相当于a的浅拷贝,当拷贝a中[3,"hello"]相当于只拷贝了一个内存地址,当劣列表里的元素改变时,b指向的内存地址并未发生改变,所以列表元素跟着一起改变

7 使用文件读取,找出文件中最长的行的长度(用一行代码解决)?

print(max([len(line) for line in open('file')]))

10 .通过函数化编程实现5的阶乘

方式一:

def func(n):
if n == 1:
return 1
else:
return n * func(n-1) obj = func(3)
print(obj) 方式二: from functools import reduce def func(number):
obj = reduce(lambda x,y:x*y,range(1,number + 1))
return obj print(func(4))

11 打印如下图案:


***
*****
*******
*****
***
* def func(number):
for i in range(1,number,2):
print(("*" * i).center(number))
for i in range(number,0,-2):
print(("*" * i).center(number)) func(7)

12.

def outer():
count = 10
def inner():
nonlocal count #nonlocal 作用于外部作用域
count = 20
print(count)
inner()
print(count)
outer() 1.分析运行结果?
20
10
2.如何让两个打印都是20 def outer():
count = 10
def inner():
nonlocal count #nonlocal 作用于外部作用域
count = 20
print(count)
inner()
print(count)
outer()

  

13 输入一个年份,判断是否是闰年?

def func(year):
if (year%4 == 0 and year%100 != 0) or year%400 == 0:
return True
else:
return False print(func(2005)) judge = lambda year: True if (year%4 == 0 and year%100 != 0) or (year%400 == 0) else False
print(judge(2004))  

14 任意输入三个数,判断大小?

def func(a,b,c):
if a >b:
if a >c:
print("%s最大"% a)
else:
print("%s最大" % c)
else:
if b >c:
print("%s最大" % b)
else:
print("%s最大" % c) func(1,2,3)

15 求s=a+aa+aaa+aaaa+aa...a的值,其中a是一个数字。例如2+22+222+2222+22222,几个数相加以及a的值由键盘控制。

def func(number,count):
ret = 0
if int(count) > 1:
for i in range(1,int(count) + 1 ):
ret += int((str(number) * i))
return ret
else:
return number obj = func(2,3)
print(obj)

16.

f=open("a")

while 1:
choice=input("是否显示:[Y/N]:")
if choice.upper()=="Y":
for i in f:
print(i)
else:
break 请问程序有无bug,怎么解决? --------------------------------结果---------------
f=open("a") while 1:
choice=input("是否显示:[Y/N]:")
if choice.upper()=="Y":
for i in f:
print(i)
f.seek(0)
else:
break f.close("a")

17
def foo():
  print('hello foo')
  return()
def bar():
  print('hello bar')

(1)为这些基础函数加一个装饰器,执行对应函数内容后,将当前时间写入一个文件做一个日志记录。
(2)改成参数装饰器,即可以根据调用时传的参数决定是否记录时间,比如@logger(True)

import time

def init(func):
def wrapper(*args,**kwargs):
a= str(time.time()) + "执行%s\n" % func
with open("record.txt","a+") as f:
f.write(a)
func(*args,**kwargs)
return wrapper @init
def foo():
print('hello foo')
return() @init
def bar():
print('hello bar') foo()
bar() import time def auth(flag):
def init(func):
def wrapper(*args,**kwargs):
if flag == True:
a= str(time.strftime("%Y-%m-%d %H:%M:%S", time.localtime())) + "执行%s\n" % func
with open("record.txt","a+") as f:
f.write(a)
func(*args,**kwargs)
return wrapper
return init @auth(True)
def foo():
print('hello foo')
return() @auth(True)
def bar():
print('hello bar') foo()
bar()

18.

list3 = [
{"name": "alex", "hobby": "抽烟"},
{"name": "alex", "hobby": "喝酒"},
{"name": "alex", "hobby": "烫头"},
{"name": "alex", "hobby": "Massage"},
{"name": "wusir", "hobby": "喊麦"},
{"name": "wusir", "hobby": "街舞"},] a = [
{"name":"alex","hobby":[1,2,3,4]},
{"name":"wusir","hobby":[1,2,3,4]}
]

  

python 基础习题

19 三次登陆锁定:要求一个用户名密码输入密码错误次数超过三次锁定?

accounts = {}

def lock_user(name):
with open("lock_user", mode="r+", encoding="utf8") as f_lock:
for line in f_lock:
if line.strip().split()[0] == name:
print("Lock user")
exit() def lockd_user(**kwargs):
with open("lock_user",mode="a+",encoding="utf8") as f_lockd_user:
for key in kwargs:
if kwargs[key] >2:
f_lockd_user.write(key + "\n") def check_user(name,passwd):
with open("user",mode="r",encoding="utf8") as f_check:
for line in f_check:
if name == line.strip().split()[0]:
if passwd == line.strip().split()[1]:
print("Success")
exit()
else:
add_error(name)
return name
return name def add_error(name):
if accounts:
if name in accounts:
accounts[name] += 1
else:
accounts[name] = 1
else:
accounts[name] = 1 def main():
count = 0
while True:
name = input("input name: ")
passwd = input("input passwd: ")
lock_user(name) #判断用户是否锁定
name = check_user(name,passwd) #判断用户
count += 1
if count > 2:
lockd_user(**accounts)
print("exit than three")
break if __name__ == '__main__':
main()