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How to Open a File in Python –

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how to open a file in python

What is Python – Python is an easy-to-interpret and high-level object-oriented programming language with easy-to-read syntax. Many people are switching to Python as it is can be used as a general-purpose, beginner-friendly programming language in web development, and automation. A common function python can be used for is opening and manipulating files with ease. In this article we will showq you how to open a file in Python.

Python provides easy-to-use inbuilt functions for creating, writing, and reading files. So what is a file? , When you use an operating system like Windows, a file could could be anything from an image or video, a document, to an executables or system file needed for the operating system or program to run. At the higher level, files are simply named locations on a disk drive with related data stored in them.

There are two types of files that can be handled in Python, normal text files and binary files (written in binary language, 0s, and 1s). Understanding the contrast between them is critical before you learn how to work with Python files.

  • Text files: In this type of file, each line of text is terminated with a special character called EOL (End of Line), which is the new line character (‘n’) in Python by default. In the case of CSV(Comma Separated Files, the EOF is a comma by default.
  • Binary files: In this type of file, there is no terminator for a line, and the data is stored after converting it into machine-understandable binary language, i.e., 0 and 1 format.

How to open a file in Python

Opening a file refers to getting the file ready either for reading or for writing. To open a file in Ptython, you simply use a the open() function. When usinmg this function, you will be requireed to also include two arguments. One that accepts the file name and another that accepts the mode(Access Mode).

Syntax:

File_object = open(r"File_Name", "Access_Mode")

Access modes

What is the access mode? Access modes govern the type of operations possible in the opened file. It refers to how the file will be used once it’s opened. These modes also define the location of the File Handle in the file. File handle is like a cursor, which defines from where the data has to be read or written in the file. There are 6 access modes in python.

Read only – r Opens a file for reading (default)
Read and Write – r+ Open the file for reading and writing. The handle is positioned at the beginning of the file. Raises I/O error if the file does not exist.
Write Only – w Open a file for writing. If a file already exists, it deletes all the existing contents and adds new content from the start of the file.
Write and Read – w+ Open the file for reading and writing. For existing files, data is truncated and over-written. The handle is positioned at the beginning of the file.
Exclusive creation – x Open a file for exclusive creation. If the file already exists, this operation fails.
Append only – a Open a file in the append mode and add new content at the end of the file.
Append and Read – a+ Open the file for reading and writing. The file is created if it does not exist. The handle is positioned at the end of the file. The data being written will be inserted at the end, after the existing data.
Read only (Binary format) – b Open the file in binary mode.
Read and Write in Binary Format – rb+ It lets the user open the file for reading and writing in binary format.
Write Only in Binary Format – wb It lets the user open the file for writing in binary format. When a file gets opened in this mode, there are two things that can happen mostly. A new file gets created if the file does not exist. The content within the file will get overwritten if the file exists and has some data stored in it. 
Write and Read in Binary Format – wb+ It lets the user open the file for reading as well as writing in binary format. When a file gets opened in this mode, there are two things that can mostly happen. A new file gets created for writing and reading if the file does not exist. The content within the file will get overwritten if the file exists and has some data stored in it. 
Append only in Binary Format – ab It lets the user open the file for appending in binary format. A new file gets created if there is no file. The data will be inserted at the end if the file exists and has some data stored in it. 
Append and Read in Binary Format – ab+ It lets the user open the file for appending and reading in binary format. A new file will be created for reading and appending if the file does not exist. We can read and append if the file exists and has some data stored in it.  
Text only – t Opens a file in a text mode (default).
Open file for Updating – + Open a file for updating (reading and writing).

Closing a File in Python

Now that we know how to open a file in Python, we need to make sure that the file will be closed properly after completing the file operation. It is a bad practice to leave your files open.

In Python, It is very important to close a file once the job is done mainly for the following reasons: –

  • It releases the resources that have been tied up with the file. By this space in the RAM can be better utilized and ensures a better performance.
  • It ensures better garbage collection.
  • There is a limit to the number of open files in an application. It is always better to close the file to ensure that the limit is not crossed.
  • If you open the file in write or read-write mode, you don’t know when data is flushed.

A file can be closed just by calling the close() function as follows.

Summary

In this tutorial, we have covered how to open a file in Python and the different access modes that can be used.

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