Python File Existence

In Python, you can use the os module to check whether a specific file or directory exists in a specified path. The os.path module provides several methods for checking file existence, including exists() and isfile().

Checking for File Existence

To check whether a file exists, use the exists() method in the os.path module. Below is a sample code snippet:

import os

filename = 'example.txt'
if os.path.exists(filename):
print('File exists')
else:
print('File does not exist')

If there is a file named example.txt in the current working directory, the output is File exists; otherwise, the output is File does not exist.

Checking if a file is a file

The os.path module can also be used to check whether a specified path is a file. This can be done using the isfile() method. Below is a sample code:

import os

filename = 'example.txt'
if os.path.isfile(filename):
print('{} is a file'.format(filename))
else:
print('{} is not a file'.format(filename))

If there is a file named example.txt in the current working directory, the output is example.txt is a file; otherwise, the output is example.txt is not a file.

Checking if a Folder Exists

To check if a folder exists, use the exists() method in the os.path module. Below is a sample code:

import os

dirname = 'data'
if os.path.exists(dirname):
print('Folder exists')
else:
print('Folder does not exist')

If there is a folder named data in the current working directory, the output is Folder exists; otherwise, the output is Folder does not exist.

Checking if a Folder is a File

The os.path module can also be used to check whether a specified path is a folder. This can be done with the isdir() method. Below is a sample code:

import os

dirname = 'data'
if os.path.isdir(dirname):
print('{} is a folder'.format(dirname))
else:
print('{} is not a folder'.format(dirname))

If there is a folder named data in the current working directory, the output is data is a folder; otherwise, the output is data is not a folder.

Checking Whether a Specified File Exists in a Folder

To check whether a specific file exists in a specific folder, use the join() method in the os.path module to generate a path, and then use the exists() method to check whether the file exists in the specified path. The following is a sample code:

import os

dirname = 'data'
filename = 'example.txt'
filepath = os.path.join(dirname, filename)

if os.path.exists(filepath):
print('{} file exists in {} folder'.format(filename, dirname))
else:
print('{} file does not exist in {} folder'.format(filename, dirname))

If there is a folder named data in the current working directory and a file named example.txt in that folder, then the output is example.txt file exists in the data folder; otherwise, the output is example.txt file does not exist in the data folder.

Conclusion

There are several ways to check for the existence of a file in Python. You can use the exists() and isfile() methods in the os.path module to check for the existence of a file, and the isdir() method to check for the existence of a folder. Additionally, you can use the join() method to generate a file path with a specified path for checking. These methods make checking for file existence a simple and quick task.