Python Check If File Exists And Create Example

This article contains some examples about file operation. They are listed as below.

  1. Check if a file exist or not.
  2. Check if a file is a directory or a file.
  3. Check if the file is readable, writable or executable.
  4. How to create a new file.
  5. How to create a new directory.
  6. How to change file permission.

1. Check File/Folder Existence.

There are three methods that can check file or folder existence.

  1. Use os.path.exists method.
  2. Catch FileNotFoundError object.
  3. Use pathlib module. This module is a built-in module in Python3 but if you use Python2, you need to install it separately.

2. Check If A Path Is Directory Or File.

  1. Use os.path.isfile method.
  2. Use pathlib.is_file or pathlib.is_dir method.

3. Check File Readable, Writable Or Executable Status.

  1. Use os.access method.

4. Create New File.

  1. Open a file object.
  2. Call file object write method.

5. Create New Directory.

  1. Use os.mkdir method.

6. Change File Permission.

  1. Use os.chmod method.

7. Code Examples.

Below is the code example, each method comments tells it’s function.

'''
Created on Aug 18, 2018
@author: zhaosong
'''

import os, stat
import pathlib

# Check file/folder existence by os.path.exists method.
def checkFileExistByOSPath(file_path):

    ret = False
    # If this file object exist.
    if(os.path.exists(file_path)):
        ret = True
        print(file_path + " exist.")
        # If this is a file.
        if(os.path.isfile(file_path)):
            print(" and it is a file.")
        # This is a directory.    
        else:
            print(" and it is a directory.")
    else:
        ret = False
        print(file_path + " do not exist.")
        
    return ret

# Check file/folder existence by exception.         
def checkFileExistByException(file_path):
    ret = True
    try:
        # Open file object.
        file_object = open(file_path, 'r')
        # Read entire file content data.
        file_data = file_object.read()
        print(file_path + " exist. It's data : " + file_data)
    except FileNotFoundError:
        ret = False
        print(file_path + " do not exist.")
    except IOError:
        ret = False
        print(file_path + " can not be read. ")    
    except PermissionError:
        ret = False
        print("Do not have permission to read file " + file_path)

    return ret

# Check file/folder existence by pathlib.         
def checkFileExistByPathlib(file_path):
    ret = True
        
    # Create path lib object.
    pl = pathlib.Path(file_path)
    
    # Check whether the path lib exist or not.
    ret = pl.exists()
    
    if(ret):
        print(file_path + " exist.")
    else:
        print(file_path + " do not exist.")
    
    if(pl.is_file()):
        print(file_path + " is a file.")
       
    if(pl.is_dir()):
        print(file_path + " is a directory.")
    
    return ret

# Check file/folder status by os.access method.
def checkFileStatusByOSAccess(file_path):
    # If this file exist.
    if(os.access(file_path, os.F_OK)):
        print(file_path + " exist.")
    else:
        print(file_path + " do not exist.")
            
    if(os.access(file_path, os.R_OK)):
        print(file_path + " is readable.")
        
    if(os.access(file_path, os.W_OK)):
        print(file_path + " is writable.")    
        
    if(os.access(file_path, os.EX_OK)):
        print(file_path + " is executable.")

# Create a new file and write some text in it.
def createNewFile(file_path):
    file_object = open(file_path, 'w')
    file_object.write('File is created.')
    print(file_path + " has been created. ")
    
# Create a new directory.
def createNewFolder(file_path):
    if(not checkFileExistByOSPath(file_path)):
        os.mkdir(file_path)
        print(file_path + " has been created. ")

# Change the file permission to read and execute only.
def setFilePermission(file_path):
    os.chmod(file_path, stat.S_IEXEC | stat.S_IREAD)
     
        
if __name__ == '__main__':
    file_folder = "./test"
    createNewFolder(file_folder)
    
    file_path = file_folder + "/abc.txt"
    # Check file existence.
    # fileExist = checkFileExistByException(file_path)
    # fileExist = checkFileExistByOSPath(file_path)
    fileExist = checkFileExistByPathlib(file_path)
    # If file do not exist then create it.
    if(not fileExist):
        createNewFile(file_path)
        setFilePermission(file_path)

    checkFileStatusByOSAccess(file_path)
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