实验目的：

理解并掌握文件操作和目录操作的相关方法，以及二进制文件的序列化和反序列化方法。能够熟练应用os模块和os.path模块进行文件和目录操作。

实验内容：

使用pickle模块将包含学生成绩的字典保存为二进制文件，然后再读取内容并显示。

Console
熊大
熊二
笨笨
{‘熊大’: 60, ‘熊二’: 70, ‘笨笨’: 80}

import pickle

a='熊大'
b='熊二'
c='笨笨'
dic={'熊大':60,'熊二':70,'笨笨':80}
data=(a,b,c,dic)

with open('pickle.date','wb') as f:
    try:
        pickle.dump(len(data),f)
        for item in data:
            pickle.dump(item,f)
    except:
        print('写文件异常')
with open('pickle.date','rb') as f:
    n=pickle.load(f)
    for i in range(n):
        x=pickle.load(f)
        print(x)

编写代码，将当前工作目录修改为“C:\”，并验证，最后将当前工作目录恢复为原来的目录。

import os
os.getcwd()

Console:
‘C:\Python34’

os.chdir(r'c:\\')
os.getcwd()

Console:
‘c:\’

>>> os.chdir(r'c:\Python34')
>>> os.getcwd()

Console:
‘c:\Python34’

编写程序，用户输入一个目录和一个文件名，搜索该目录及其子目录中是否存在该文件，如果存在，就输出该文件的路径。效果如下:

Console:
folder path:D:
file path:新建文本文档.txt
D:\QQDownload\新建文本文档.txt

import os
def search_currentfolder(folder, filename):
    try:
        files = os.listdir(folder)
    except:
        print(folder,"文件访问否认")
        return None

    if files.__contains__(filename):
        return os.path.join(folder, filename)
    else:
        return None
def search_allfolder(folder, filename):
    filepath = search_currentfolder(folder,filename)
    if filepath:
        return filepath
    else:
        try:
            files = os.listdir(folder)
        except:
            return None
        folders = list(map(lambda name:folder+"\\"+name, filter(lambda path: not path.__contains__("."), files)))
        if not folders:
            return None
        for folderpath in folders:
            if os.path.isdir(folderpath):
                filepath = search_allfolder(folderpath, filename)
                if filepath:
                    return filepath
    return None
def search(folder,filename,model="current"):
    if model=="all":
        filepath = search_allfolder(folder,filename)
    else:
        filepath = search_currentfolder(folder, filename)
    if filepath:
        print(filepath)
    else:
        print("否")

folder = input("folder path:")
filename = input("file path:")
search(folder,filename,model = "all")