Work with SVG Attributes in Python

Quick Answer

Use Element.get_attribute() to read an SVG attribute, set_attribute() to add or update it, has_attribute() to check whether it exists, and remove_attribute() to delete it. After modifying SVG attributes, call document.save(output_path) to save the updated SVG file.

SVG Attribute Editing Basics

SVG attributes define geometry, styling, references, transforms, accessibility metadata, and document layout. Common examples include width, height, viewBox, x, y, cx, cy, r, fill, stroke, stroke-width, transform, href, and id.

Use this article when the task is specifically about reading, changing, checking, or removing SVG attributes. If you need to create elements or change the full document structure, see Edit SVG File. If you need to find target elements first, see Navigate SVG.

Before running the examples, install Aspose.SVG for Python via .NET in your Python environment.

Aspose.SVG APIs Used

API	Purpose
SVGDocument	Loads, creates, edits, and saves SVG documents
Element.get_attribute()	Reads an attribute value from an SVG element
Element.set_attribute()	Adds or updates an SVG attribute
Element.has_attribute()	Checks whether an element has a specified attribute
Element.remove_attribute()	Removes an attribute from an SVG element
Element.query_selector()	Finds an element before reading or editing its attributes

Get SVG Element Attributes

Use get_attribute() when you know the attribute name and want to read its current value. This is useful before changing a file, validating generated SVG, or extracting values such as viewBox, fill, or transform.

The following example loads an SVG file, finds the first <circle> element, and prints several attribute values.

import os
from aspose.svg import SVGDocument

# Read attributes from the first circle element
input_folder = "data/"
input_path = os.path.join(input_folder, "shapes.svg")

with SVGDocument(input_path) as document:
    circle = document.root_element.query_selector("circle")

    if circle is not None:
        print("cx:", circle.get_attribute("cx"))
        print("cy:", circle.get_attribute("cy"))
        print("fill:", circle.get_attribute("fill"))

If the attribute is missing, the returned value can be empty. Check the source markup or use has_attribute() when your code must distinguish between a missing attribute and an empty value.

Set SVG Attributes

Use set_attribute() to add a new attribute or update an existing one. The method stores the value as text, so SVG numeric values, colors, lengths, and transform values should be passed as strings.

The following example creates a simple SVG, sets root attributes and circle attributes, adds the circle to the DOM, and saves the result.

from aspose.svg import SVGDocument

# Create an SVG circle by setting root and element attributes
with SVGDocument() as document:
    svg_element = document.root_element
    svg_element.set_attribute("width", "160")
    svg_element.set_attribute("height", "160")
    svg_element.set_attribute("viewBox", "0 0 160 160")

    circle = document.create_element_ns("http://www.w3.org/2000/svg", "circle")
    circle.set_attribute("cx", "80")
    circle.set_attribute("cy", "80")
    circle.set_attribute("r", "52")
    circle.set_attribute("fill", "#ff7f50")
    circle.set_attribute("stroke", "#2f4f4f")
    circle.set_attribute("stroke-width", "6")
    svg_element.append_child(circle)

    document.save("set-svg-attributes.svg")

The saved SVG contains a visible circle because the example sets both geometry attributes and styling attributes, then appends the element to the root <svg> element.

Check and Remove SVG Attributes

Use has_attribute() before reading or removing optional attributes. Use remove_attribute() when you want the element to fall back to inherited styles, CSS rules, or default SVG behavior.

The following example removes the inline fill attribute from the first circle only if that attribute exists, then saves the edited SVG.

import os
from aspose.svg import SVGDocument

# Remove an inline fill attribute from the first circle element
input_folder = "data/"
output_folder = "output/"
input_path = os.path.join(input_folder, "shapes.svg")
output_path = os.path.join(output_folder, "circle-fill-removed.svg")
os.makedirs(output_folder, exist_ok=True)

with SVGDocument(input_path) as document:
    circle = document.root_element.query_selector("circle")

    if circle is not None and circle.has_attribute("fill"):
        circle.remove_attribute("fill")

    document.save(output_path)

Removing an attribute is different from setting it to an empty string. Removing it deletes the attribute from the element markup, which can change how CSS inheritance or default SVG rendering applies.

Update Attributes for Multiple Elements

When you need to update many elements, first find the target group of elements, then set the same attribute on each one. Tag-name search is often enough when all elements of one type need the same update.

The following example updates every <rect> element in an SVG file and saves the result.

import os
from aspose.svg import SVGDocument

# Update stroke attributes for all rectangle elements
input_folder = "data/"
output_folder = "output/"
input_path = os.path.join(input_folder, "shapes.svg")
output_path = os.path.join(output_folder, "rectangles-updated.svg")
os.makedirs(output_folder, exist_ok=True)

with SVGDocument(input_path) as document:
    for rect in document.get_elements_by_tag_name("rect"):
        rect.set_attribute("stroke", "#00838f")
        rect.set_attribute("stroke-width", "4")

    document.save(output_path)

For more selective updates, combine this approach with CSS selectors or XPath queries described in Navigate SVG.

Common Mistakes and Fixes

Problem	Likely cause	Fix
Attribute value is empty	The attribute is missing or the value is defined in style or CSS	Use has_attribute() and inspect style when needed
Shape does not appear after setting attributes	The element was not added to the DOM or required geometry attributes are missing	Call append_child() and set geometry attributes such as cx, cy, r, width, or height
Saved SVG is unchanged	The document was not saved after editing	Call document.save(output_path) after attribute updates
Removing an attribute changes styling unexpectedly	The element starts using inherited styles, CSS rules, or SVG defaults	Check parent styles and CSS rules before removing styling attributes
Multiple elements were not updated	The code found only the first matching element	Use tag-name search, query_selector_all(), or XPath when all matches must change

FAQ

How do I get an SVG attribute in Python?

Find the target element and call element.get_attribute(attribute_name), for example circle.get_attribute("fill").

How do I set an SVG attribute in Python?

Call element.set_attribute(name, value). Pass attribute values as strings, such as set_attribute("stroke-width", "4").

How do I check whether an SVG attribute exists?

Use element.has_attribute(attribute_name) before reading or removing optional attributes.

How do I remove an SVG attribute?

Call element.remove_attribute(attribute_name) and save the document after the change.

Can I update attributes for many SVG elements at once?

Yes. Iterate through elements returned by get_elements_by_tag_name(), query_selector_all(), or an XPath query, then call set_attribute() for each element.

Related Articles

• Edit SVG File explains how to add and modify SVG elements.
• Navigate SVG shows how to find elements with tag-name search, CSS selectors, and XPath.
• Create SVG File explains how to create blank SVG documents and load existing SVG files.
• Save SVG File explains how to save edited SVG documents and linked resources.
• Convert SVG Files in Python covers exporting edited SVG documents to PDF, PNG, JPG, and other formats.