File handling is an important part of any web application.
Python has several functions for creating, reading, updating, and deleting files.
File Handling
The key function for working with files in Python is the open() function.
The open() function takes two parameters; filename, and mode.
There are four different methods (modes) for opening a file:
<p><code class="w3-codespan">"r"</code> - Read - Default value. Opens a
file for reading, error if the file does not exist</p>
<p><code class="w3-codespan">"a"</code> - Append - Opens a file for
appending, creates the file if it does not exist</p>
<p><code class="w3-codespan">"w"</code> - Write - Opens a file for writing,
creates the file if it does not exist</p>
<p><code class="w3-codespan">"x"</code> - Create - Creates the specified file, returns
an error if the file exists</p>
In addition you can specify if the file should be handled as binary or text mode
<p><code class="w3-codespan">"t"</code> - Text - Default value. Text mode</p>
<p><code class="w3-codespan">"b"</code> - Binary - Binary mode (e.g.
images)</p>
Syntax
To open a file for reading it is enough to specify the name of the file:
f = open("demofile.txt")
The code above is the same as:
f = open("demofile.txt", "rt")
Because "r" for read, and "t" for text are the default values, you do not need to specify them.
Note: Make sure the file exists, or else you will get an error.
