Python3.2 实现zip压缩与解压缩功能

刚接触Python，用Python3试着写了一个Zip文件的压缩和解压缩脚本，不足之处，欢迎拍砖
功能有限，要按照脚本压缩文件或者文件夹，必须进入文件所在目录，以文件所在目录为工作路径，并且默认压缩后的文件名同于原文件所在的目录名、解压后的文件夹名同于解压前的文件名
压缩功能分为压缩所在目录的所有文件跟部分文件（部分文件需要手动添加文件名）；解压功能分为解压到当前目录跟解压到指定目录，以下为代码：

]#!/usr/bin/env python3
import os,zipfile
def Zip(target_dir):
target_file=os.path.basename(os.getcwd())+'.zip'
zip_opt=input("Will you zip all the files in this dir?(Choose 'n' you should add files by hand)y/n: ")
while True:
if zip_opt=='y':       #compress all the files in this dir
filenames=os.listdir(os.getcwd())    #get the file-list of this dir
zipfiles=zipfile.ZipFile(os.path.join(target_dir,target_file),'w',compression=zipfile.ZIP_DEFLATED)
for files in filenames:
zipfiles.write(files)
zipfiles.close()
print("Zip finished!")
break
elif zip_opt=='n':     #compress part of files of this dir
filenames=list(input("Please input the files' name you wanna zip:"))
zipfiles=zipfile.ZipFile(os.path.join(target_dir,target_file),'w',compression=zipfile.ZIP_DEFLATED)
for files in filenames:
zipfiles.write(files)
zipfiles.close()
print("Zip finished!")
break
else:
print("Please in put the character 'y' or 'n'")
zip_opt=input("Will you zip all the files in this dir?(Choose 'n' you should add files by hand)y/n: ")
def Unzip(target_dir):
target_name=input("Please input the file you wanna unzip:")
zipfiles=zipfile.ZipFile(target_name,'r')
zipfiles.extractall(os.path.join(target_dir,os.path.splitext(target_name)[0]))
zipfiles.close()
print("Unzip finished!")
def main():
opt=input("What are you gonna do?Zip choose 'y',unzip choose 'n'.y/n: ")
while True:
if opt=='y':  #compress files
zip_dir=input("Please input the absdir you wanna put the zip file in:")
Zip(zip_dir)
break
elif opt=='n':  #unzip files
unzip_dir=input("Please input the absdir you wanna put the zip file in(Nothing should be done if you wann unzip files in the current dir):")
if unzip_dir=='':
Unzip(os.getcwd())
else:
Unzip(unzip_dir)
break
else:
print("Please input the character 'y' or 'n'")
opt=input("What are you gonna do?Zip choose 'y',unzip choose 'n'.y/n: ")
if __name__=='__main__':
main()