Question

在Python上，我需要帮助搜索具有特定标题类型的文件（PST文件，标题序列21 42 44 4E），然后将它们复制到我保存的文件目录中。

以下是我的代码的相关摘录。

# get working directory of my program
ori_path=os.getcwd()
# this is where the file is saved(from the root directory of my program)
temp = "\etc\Saved Files"
# obtain value written in textbox, the path to search
path_to_copy_from=self.textbox.GetValue()
# create the absolute destination path so that the files don't end up somewhere they shouldn't be  
copy_path="{}{}".format(ori_path,temp)     
# change working directory to the one specified by user
os.chdir(path_to_copy_from)

我将使用shutil进行这样的复制：

shutil.copy(files,copy_path)

我发现使用itertools提到的一些搜索，但我无法理解这个例子（因此，我为什么要问这个问题）。我需要帮助来提供将查看文件头的代码，然后如果头与PST头格式匹配则调用shutil。

Answer 1

从问题中获取十六进制格式的文件的前4个字节：

header = ""
with open(path_to_copy_from, 'rb') as f:
    for i in range(4):
        byte = f.read(1)
        header += hex(ord(byte))[2:] + " "

然后，您可以检查文件夹中的每个文件，这个header字符串是否与您要查找的字符串匹配。

Answer 2

使用junuxx的解决方案，我找到了一种方法来为目录中的所有文件执行此操作。最终的代码看起来像这样

     import wx #this is for GUI interfaces i made to interact with the user. aka wxPython
     import os
     import glob
     import shutil
     #the above are the needed libraries. 
     path_to_copy_from=self.textbox.GetValue() #obtain value written in textbox(made with wxPython)
     if os.path.exists(path_to_copy_from):
        ori_path=os.getcwd()#get working directory of my program
        #combine ori_path and temp to create the destination path for files to be copied to
        copy_path="{}{}".format(ori_path,temp)
        #change working directory to the one specified by user
        os.chdir(path_to_copy_from)
            #to copy files based on header
            header = ""
            pst_header="21 42 44 4e "
            for self.files in glob.glob("*.*"):
                try:
                    with open(self.files, 'rb') as f:
                        for i in range(4):
                            byte = f.read(1)
                            header += hex(ord(byte))[2:] + " "

                        if header == pst_header:
                            shutil.copy(self.files,copy_path)
                            #the following 2 lines tells the user using a textbox i made earlier that something is happening. made for a textctrl i made with wxPython
                            self.textbox2.AppendText("Found file with .pst header.\n")
                            self.textbox2.AppendText("Copied {} to {}. \n".format(self.files,copy_path))
                            #to change copied file to read only
                            path_to_file="{}\{}".format(copy_path,self.files)
                            #set the file as read-only(for my program only, not necessary to have)
                            os.chmod(path_to_file,0444)
                        #to remove the string already in header for next iteration
                        header = "" 
                #simple exception handling. change as you need
                except TypeError, ex:
                    pass
                except IOError, ex:
                    pass

非常感谢：）

基于标头的python复制文件

2 个答案: