Introducing… BytesGenerator!
If you’ve ever worked with emails before, you might have noticed that they can contain binary data. This is where BytesGenerator comes in handy it allows us to generate email messages as a series of bytes instead of strings. Why would we want to do this? Well, for one thing, it makes our code more efficient and faster because we don’t need to convert everything to ASCII-compatible formats like the Generator class does (which is what you get by default).
So how do we use BytesGenerator in Python? Let me show you an example:
# Import the necessary modules
from email.generator import BytesGenerator, add_header # Import BytesGenerator and add_header functions from email.generator module
import os # Import os module for file operations
# Create a binary file-like object to write our message to
with open('myemail.bin', 'wb') as f: # Open a binary file named 'myemail.bin' in write mode and assign it to variable 'f'
# Instantiate the BytesGenerator class with our output file and some options (optional)
gen = BytesGenerator(f, mangle_from=True) # Create an instance of BytesGenerator class with 'f' as output file and set mangle_from to True to add '>' before From header
# Add headers using the add_header function from email.utils
add_header(gen, 'From', '[email protected]') # Add From header to the message
add_header(gen, 'Subject', 'This is a binary message!') # Add Subject header to the message
# Write some binary data to our message (in this case, an image)
with open('image.png', 'rb') as img: # Open an image file named 'image.png' in read binary mode and assign it to variable 'img'
gen.write(b'--myemail\r\nContent-Type: image/png\r\nContent-Transfer-Encoding: base64\r\n\r\n') # Write the necessary headers for the image to the message
while True: # Start a loop
data = img.read(1024) # Read 1024 bytes of data from the image file and assign it to variable 'data'
if not data: break # If there is no data left to read, break out of the loop
gen.write(data) # Write the data to the message
# Close our message with a boundary and an end of transmission marker
gen.write(b'\r\n--myemail--') # Write the end boundary and end of transmission marker to the message
In this example, we’re creating a binary email message that includes an image attachment. We first create a BytesGenerator object called `gen`, which takes the output file (in this case, ‘myemail.bin’) and some optional arguments like `mangle_from`. Then we add headers using the `add_header` function from the `email.utils` module.
Next, we write our binary data to the message by opening an image file in read-binary mode (using `’rb’`) and reading it one chunk at a time until there is no more data left. We also add some headers for the attachment using the same function as before. Finally, we close our message with a boundary and end of transmission marker.
And that’s it! Our binary email message is now ready to be sent or saved for later use.
It might not be the most exciting feature, but it can definitely save us some time and resources when working with emails that contain binary data.