Python file and Directory operations method Daquan (with instance)

One, python in the file, folder operations often used in the OS module and Shutil module common methods.

1 get the current working directory, that is, the directory path of the current Python script work: OS.GETCWD ()2 returns all files and directory names under the specified directory name: Os.listdir ()3 function to delete a file: Os.remove ()4 Delete Multiple directories: Os.removedirs (r "C:\python")5 verifies whether the given path is a file: Os.path.isfile ()6 Verify that the given path is a directory: Os.path.isdir ()7 determine if it is an absolute path: Os.path.isabs ()8 Verify that the given path is really saved: os.path.exists ()9Returns the directory name and file name of a path: Os.path.split () eg Os.path.split ('/home/swaroop/byte/code/poem.txt') Results: ('/home/swaroop/byte/code','Poem.txt'). Detach extension: Os.path.splitext ()Ten Get path name: Os.path.dirname () One Get file name: Os.path.basename () A Run shell command: Os.system () - Read and SET environment variables: os.getenv () and os.putenv () -Gives the line terminator used by the current platform: Os.linesep Windows uses'\ r \ n', Linux uses'\ n'and Mac uses'\ r' theIndicates the platform you are using: Os.name for Windows, it is'NT', and for Linux/unix users, it is'POSIX' - Rename : Os.rename (old, new) - Create a multilevel directory: Os.makedirs (r "C:\python\test") - Create a single directory: Os.mkdir ("Test") + get file attributes: Os.stat (file) - modify file permissions and timestamps: Os.chmod (file) + Terminate Current process: Os.exit () AGet File Size: os.path.getsize (filename)

Second, the file operation method Daquan:
1.os.mknod ("Test.txt") #创建空文件
2.FP = open ("Test.txt", W) #直接打开一个文件, create file If file does not exist
3. About open mode:

w: Open as Write, a: Open in Append mode (start with EOF, create new file if necessary) R+: Open w+: Open in read/write mode(see W) a+: Open in read/write mode (see a) RB: Open WB in binary read mode: Open in binary write mode (see W) AB: Open in binary append mode (see a) RB+: Open in binary read/write mode (see r+ ) WB+: Open in binary read/write mode (see w+ ) ab+: Open in binary read/write mode (see A +)

fp.read ([size]) #size is the length of the read, in bytes fp.readline ([size]) #read a line, if a size is defined, it is possible to return only part of a rowfp.write (str) #writes STR to a file, write () does not add a newline character after Strfp.close () #close the file. Python will automatically close files after a file is not used, but this feature is not guaranteed and it is best to develop a habit of shutting them down. If a file is closed and then manipulated, it generates ValueErrorFp.flush () #write the contents of the buffer to the hard disk Fp.tell () #returns the current position of the file action tag, starting with the origin of the fileFp.next () #returns the next line and shifts the file action marker to the next line. When a file is used for a statement such as for ... in file, it is called the next () function to implement the traversal. Fp.seek (offset[,whence]) #moves the file-action marker to the location of offset. This offset is generally relative##于文件的开头来计算的, usually a positive number. However, if the whence parameter is provided, the whence can be##以为0表示从头开始计算, 1 indicates the origin is calculated at the current position. 2 indicates the origin of the end of the file is counted.#count. Note that if the file is opened in a or a + mode, the file action tag will automatically return each time the write operation#to the end of the file. fp.truncate ([size]) #The file is cut to the specified size, the default is the location of the current file operation tag. If#size is larger than the file, depending on the system may not change the file, it may be 0 files to the corresponding#size, it may also be added to some random content. 

Three, directory operation method Daquan

1. Create Directory Os.mkdir ("file")2. Copy files: Shutil.copyfile ("Oldfile","NewFile")#Oldfile and NewFile can only be files .Shutil.copy ("Oldfile","NewFile")#Oldfile can only be a folder, NewFile may be a file, or it can be a destination directory3. Copy folder:4.shutil.copytree ("Olddir","Newdir")#Olddir and Newdir can only be directories, and newdir must not exist5. Rename file (directory) Os.rename ("oldname","newname")#the file or directory is used by this command6. moving files (directories) Shutil.move ("Oldpos","Newpos")7. Delete File Os.remove ("file")8. Delete directory Os.rmdir ("dir")#only empty directories can be deletedShutil.rmtree ("dir")#empty directories, contents of the directory can be deleted9. Convert Catalog Os.chdir ("Path")#Change Path

Iv. Examples of comprehensive documentation operations

Add ' _fc ' to all picture names under folder
Python code:

#-*-coding:utf-8-*-ImportReImportOSImport Time#str.split (String) split string#' connectors '. Join (list) to make a list of stringsdefchange_name (path):GlobalIif  notOs.path.isdir (PATH) and  notos.path.isfile (path):returnFalseifos.path.isfile (path): File_path= Os.path.split (path)#splitting out directories and filesLists = File_path[1].split ('.')#splitting out files with file name extensionsFile_ext = Lists[-1]#Remove suffix name (list slice operation)Img_ext = ['BMP','JPEG','gif','PSD','PNG','jpg']        ifFile_extinchimg_ext:os.rename (Path,file_path[0]+'/'+lists[0]+'_fc.'+file_ext) I+=1#Note that I here is a trap.        #or        #img_ext = ' bmp|jpeg|gif|psd|png|jpg '        #if File_ext in Img_ext:        #print (' OK---' +file_ext)    elifOs.path.isdir (path): forXinchOs.listdir (path): Change_name (Os.path.join (path,x))#Os.path.join () is useful for path processingImg_dir='d:\\xx\\xx\\images'Img_dir= Img_dir.replace ('\\','/') Start=time.time () I=0change_name (img_dir) C= Time.time ()-StartPrint('program run time:%0.2f'%(c))Print('processed%s picture in total'% (i))

Python file and Directory operations method Daquan (with instance)