File open and close in python

By: Rajesh P.S.

Python features an intrinsic open() function designed for file access, which returns a file object upon execution. These file objects encapsulate a range of methods and attributes, facilitating both the retrieval of file-related information and the manipulation of the file itself.

Open a file in Python

my_file = open(filename, filemode)

The parameter "filename" is a string argument that denotes the desired filename along with its corresponding path. The "filemode" parameter, also in string format, serves to determine the intended purpose of the file, such as reading or writing. Subsequently, "my_file" functions as a file handler object, commonly referred to as a file pointer, facilitating the interaction and manipulation of the designated file.

example

my_file = open("my_file.txt", "r") # Open a file print ("Name of the file: ", my_file.name) print ("Opening mode : ", my_file.mode)

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output

Name of the file: my_file.txt Opening mode : r

In the above example, open a text file called "my_file.txt" in reading only mode. The print its file name and file mode.

Close a file in Python

When you're done with a file, it is advisable to utilize the close() method to terminate the connection and release the resources that were associated with the file, effectively freeing them up for other operations. This step ensures proper resource management within your Python program.

example

my_file = open("my_file.txt", "r") # Open a file # do file operations. my_file.close()

It's crucial to emphasize the practice of consciously closing each open file once its intended purpose has been fulfilled and there's no longer a need to maintain it in an open state. This consideration is particularly important due to the inherent constraint on the number of concurrently open files a program can manage. Overstepping this limit may lead to irreparable program crashes.

However, the close() method doesn't come without potential pitfalls. If an exception arises during file operations, the code may terminate without properly closing the file. To circumvent this issue, it's advisable to implement a try...finally block, ensuring proper file closure even in the presence of exceptions. This disciplined approach contributes to robust and error-resilient code execution.

example

try: my_file = open("my_file.txt", "r") # Open a file # do some file operations. finally: my_file.close()

In the above example, it is guaranteed that the file is properly closed even if an exception is raised, causing program flow to stop.

Employing the "with" statement represents the most secure approach to manage file operations in Python. This construct guarantees the automatic closure of the file when the code block encapsulated within the "with" statement concludes execution. This practice mitigates the risk of leaving files open inadvertently and ensures optimal resource management.

example

with open("my_file.txt", "r") as my_file: # do some file operations

In the above example, you don't need to explicitly call the close() method. It is done internally.

Renaming and Deleting files in python

The OS module within Python furnishes a mechanism for accessing functionalities that are contingent upon the operating system in use. Positioned within Python's repository of standard utility modules, the OS module facilitates the utilization of platform-specific capabilities. To use this module, you must initially import it, after which you gain access to its assortment of functions tailored to the operating system's specific features and requirements.

Renaming a file in Python

os.rename(old_file_name, new_file_name)

example

import os cur_file = "file1.txt" new_file = "file2.txt" os.rename(cur_file, new_file)

Deleting a file in Python

example

import os cur_file = "file1.txt" os.remove(cur_file)

Conclusion

File manipulation in Python involves the use of the open() function to access and interact with files, acquiring a file object for operations. After completion, it's imperative to employ the close() method to ensure the proper release of resources. An alternative to manual closure is the utilization of the "with" statement, which automatically manages file closure upon exiting the block.

Next > Python File Write

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