How does Python determine whether a file or folder exists?

How does Python determine whether a file or folder exists?

This article mainly describes how to determine whether a file or folder exists in Python. This article also describes how to determine whether a file or folder exists, and how to determine whether it is a file or directory. path. use lexist to determine whether a file or directory exists in FTP. For more information, see

1. python checks whether files and folders exist and creates folders

The Code is as follows:

>>> Import OS

>>> OS. path. exists ('d:/assist ')

True

>>> OS. path. exists ('d:/assist/getTeacherList. py ')

True

>>> OS. path. isfile ('d:/assist ')

False

>>> OS. path. isfile ('d:/assist/getTeacherList. py ')

True

>>> OS. makedirs ('d:/assist/set ')

>>> OS. path. exists ('d:/assist/set ')

True

Ii. python checks whether a file exists

The Code is as follows:

Import OS

Filename = R'/home/tim/workspace/test.txt'

If OS. path. exists (filename ):

Message = 'OK, the "% s" file exists .'

Else:

Message = "Sorry, I cannot find the" % s "file ."

Print message % filename

Iii. How to Use Python to determine whether a file exists

You can use the OS. path. exists () method to directly determine whether a file exists.

The Code is as follows:

The Code is as follows:

>>> Import OS

>>> OS. path. exists (r'c: \ 1. TXT ')

False

>>>

If the returned value is True or not, False is returned.

Iv. Determine whether a folder exists in python

The Code is as follows:

$ Python

Python 2.7.3 (default, Jan 2 2013, 16:53:07)

[GCC 4.7.2] on linux2

Type "help", "copyright", "credits" or "license" for more information.

>>> Import OS

>>>

>>>

>>> Tobecheckdir = R'/home/tim/workspace'

>>> OS. path. isdir (tobecheckdir)

True

>>>

5. Check whether the file exists and whether the path is a file in python.

Before writing a file, you usually need to check whether the file path is writable:

The Code is as follows:

From OS import path, access, R_ OK # W_ OK for write permission.

PATH = './file.txt'

If path. exists (PATH) and path. isfile (PATH) and access (PATH, R_ OK ):

Print "File exists and is readable"

Else:

Print "Either file is missing or is not readable"

You can also implement the following method:

The Code is as follows:

Def file_exists (filename ):

Try:

With open (filename) as f:

Return True

Handle t IOError:

Return False

6. python checks whether files and folders exist.

The Code is as follows:

Import OS

OS .path.isfile('test.txt ') # returns False if it does not exist.

OS. path. exists (directory) # If the directory does not exist, False is returned.

VII. OS. path. lexist

And OS. path. lexists (path)

True is also returned for the link file of broken.

8. Determine whether a folder exists through python FTP

How does python determine whether a folder exists? The majority of users gave the answer:

You can use the ftp library. The following is an example of Python core programming:

The Code is as follows:

>>> From ftplib import FTP

>>> F = FTP ('ftp .python.org ')

>>> F. login ('anonus us', 'guido @ python.org ')

'2017 Guest login OK, access restrictions apply .'

>>> F. dir ()

The file does not exist in the dir result.

Or:

The Code is as follows:

Try:

F. retrbinary ('retr % s' % FILE, open (FILE, 'wb '). write)

Failed t ftplib. error_perm:

Print 'error: cannot read file "% s" '% FILE 40 OS. unlink (FILE)