How to Check if a File Exists in Python with isFile() and exists()
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January 5, 2023 / #Python
How to Check if a File Exists in Python with isFile() and exists()
When working with files in Python, there may be times when you need to check whether a file exists or not.
But why should you check if a file exists in the first place?
Confirming the existence of a specific file comes in handy when you want to perform particular operations, such as opening, reading from, or writing to that file.
If you attempt to perform any of the operations mentioned above and the file doesn't exist, you will come across bugs and your program will end up crashing.
So, to perform operations and prevent your program from crashing, it is a helpful first step to check if a file exists on a given path.
Thankfully, Python has multiple built-in ways of checking whether a file exists, like the built-in os.path
and pathlib
modules.
Specifically, when using the os.path
module, you have access to:
- the
os.path.isfile(path)
method that returnsTrue
if thepath
is a file or a symlink to a file. - the
os.path.exists(path)
method that returnsTrue
if thepath
is a file, directory, or a symlink to a file.
And when using the pathlib
module, you have access to the pathlib.Path(path).is_file()
function, which returns True
if path
is a file and it exists.
In this article, you will learn how to use Python to check if a file exists using the os.path
and pathlib
modules.
Let's dive in!
How to Check if a File Exists Using the os.path
Module
The os
module is part of the standard library (also known as stdlib
) in Python and provides a way of accessing and interacting with the operating system.
With the os
module, you can use functionalities that depend on the underlying operating system, such as creating and deleting files and folders, as well as copying and moving contents of folders, to name a few.
Since it is part of the standard library, the os
module comes pre-packaged when you install Python on your local system. You only need to import it at the top of your Python file using the import
statement:
import os
The os.path
is a submodule of the os
module.
It provides two methods for manipulating files - specifically the isfile()
and exists()
methods that output either True
or False
, depending on whether a file exists or not.
Since you will be using the os.path
submodule, you will instead need to import that at the top of your file, like so:
import os.path
How to Check if a File Exists Using the os.path.isfile()
Method in Python
The general syntax for the isfile()
method looks like this:
os.path.isfile(path)
The method accepts only one argument, path
, which represents the defined path to the file whose existence you want to confirm.
The path
argument is a string enclosed in quotation marks.
The return value of the isfile()
method is either a Boolean value - either True
or False
depending on whether that file exists.
Keep in mind that if the path ends in a directory name and not a file, it will return False
.
Let's see an example of the method in action.
I want to check whether an example.txt
file exists in my current working directory, python_project
.
The example.txt
is on the same level as my Python file main.py
, so I am using a relative file path.
I store the path to example.txt
in a variable named path
.
Then I use the isfile()
method and pass path
as an argument to check whether example.txt
exists in that path.
Since the file does exist, the return value is True
:
import os.path
path = './example.txt'
check_file = os.path.isfile(path)
print(check_file)
# output
# True
Ok, but what about absolute paths?
Here is the equivalent code when using an absolute path. The example.txt
file is inside a python_project
directory, which is inside my home directory, /Users/dionysialemonaki/
:
import os.path
path = '/Users/dionysialemonaki/python_project/example.txt'
print(os.path.isfile(file_path))
# Output
# True
And as mentioned earlier, the isfile()
method only works for files and not directories:
import os.path
path = '/Users/dionysialemonaki/python_project'
check_file = os.path.isfile(path)
print(check_file)
# output
# False
If your path ends in a directory, the return value is False
.
How to Check if a File Exists Using the os.path.exists()
Method in Python
The general syntax for the exists()
method looks like this:
os.path.exists(path)
As you can see from the syntax above, the exists()
method looks similar to the isfile()
method.
The os.path.exists()
method checks to see whether the specified path exists.
The main difference between exists()
and isfile()
is that exists()
will return True
if the given path to a folder or a file exists, whereas isfile()
returns True
only if the given path is a path to a file and not a folder.
Keep in mind that if you don't have access and permissions to the directory, exists()
will return False
even if the path exists.
Let's go back to the example from the previous section and check whether the example.txt
file exists in the current working directory using the exists()
method:
import os.path
path = './example.txt'
check_file = os.path.exists(path)
print(check_file)
# output
# True
Since the path to example.txt
exists, the output is True
.
As mentioned earlier, the exists()
method checks to see if the path to a directory is valid.
In the previous section, when I used the isfile()
method and the path pointed to a directory, the output was False
even though that directory existed.
When using the exists()
method, if the path to a directory exists, the output will be True
:
import os.path
path = '/Users/dionysialemonaki/python_project'
check_file = os.path.exists(path)
print(check_file)
# output
# True
The exists()
method comes in handy when you want to check whether a file or directory exists.
How to Check if a File Exists Using the pathlib
Module
Python 3.4 version introduced the pathlib
module.
Using the pathlib
module to check whether a file exists or not is an object-oriented approach to working with filesystem paths.
Like the os.path
module from earlier on, you need to import the pathlib
module.
Specifically, you need to import the Path
class from the pathlib
module like so:
from pathlib import Path
Then, create a new instance of the Path
class and initialize it with the file path you want to check:
from pathlib import Path
# create a Path object with the path to the file
path = Path('./example.txt')
You can use the type()
function to check the data type:
from pathlib import Path
path = Path('./example.txt')
print(type(path))
# output is a pathlib object
# <class 'pathlib.PosixPath'>
This confirms that you created a Path
object.
Let’s see how to use the pathlib
module to check if a file exists using the is_file()
method, one of the built-in methods available with the pathlib
module.
How to Check if a File Exists Using the Path.is_file()
Method in Python
The is_file()
method checks if a file exists.
It returns True
if the Path
object points to a file and False
if the file doesn't exist.
Let's see an example of how it works:
from pathlib import Path
# create a Path object with the path to the file
path = Path('./example.txt')
print(path.is_file())
# output
# True
Since the example.txt
file exists in the specified path, the is_file()
method returns True
.
Conclusion
In this article, you learned how to check if a file exists in Python using the os.path
and pathlib
modules and their associated methods.
Hopefully, you have understood the differences between the modules and when to use each one.
Thank you for reading, and happy coding!
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