如何将 XML 树 object 转换为字节 stream？ Python

Question

I have a function that saves files to a db, but this one requires a bytes stream as parameter. Something like:

write_to_db("File name", stream_obj)

Now, I want to save a XML; I am using the xml library.

import xml.etree.cElementTree as ET

Is there a function that convert the xml object to bytes stream? The solution I got was:

• Save it locally with the function write
• Retrieve it with "rb" to get the file as bytes
• Now that I have the bytes stream, save it with the function mentioned
• Delete the file

Example:

# Saving xml as local file
tree = ET.ElementTree(ET.Element("Example")
tree.write("/This/is/a/path.xml")

# Reading local file as bytes
f = open("/This/is/a/path.xml", "rb")

# Saving to DB
write_to_db("File name", f) # <--- See how I am using "f" cuz I opened it as bytes with rb

# Deleting local file
os.remove("/This/is/a/path.xml")]

But is there a function from the xml library that returns automatically the bytes stream? Something like:

tree = ET.ElementTree(ET.Element("Example")
bytes_file = tree.get_bytes() # <-- Like this?

# Writing to db
write_to_db("File name", bytes_file)

This so I can prevent creating and removing the file in my repository.

Thank you in advance.

Another fast question:

Are the words "bytes stream" correct? or what is the difference? what would be the correct words that I am looking for?

Answer 1

So as Balmy mentioned in the comments, the solution is using:

ET.tostring()

My code at the end looked something like this:

# Here you build your xml
x = ET.Element("ExampleXML",{"a tag": "1", "another tag": "2"})

# Here I am saving it to my db by using the "tostring" function, 
# Which as default return the xml as a bytes stream string.
write_to_db("File name", ET.tostring(x))