How to write a binary file in Python

In the below example we show how to read a binary file in Python.

In this example, we will take a look at how to write to a binary file.

Again we will make use of the build-in open() function, and make use of the flags that will help up write a binary file from the below table.

Character	Meaning
r	open for reading (default)
w	open for writing, truncating the file first
x	open for exclusive creation, failing if the file already exists
a	open for writing, appending to the end of the file if it exists
b	binary mode
t	text mode (default)
+	open for updating (reading and writing)

We will have to make use of the w and b characters to write in binary mode.

Example:

First let's create a binary string that we want to write to the binary file.

binary_data = b'Some data to write' 

Now let's write it to a file.

with open('data_20230706.bin', 'wb') as binary_file:
    binary_file.write(binary_data)