Hello,

I have a problem where when I run my extension from the GUI i get the error:

Traceback (most recent call last):
  File "my_first_extension.py", line 3, in <module>
    class MyFirstExtension(inkex.EffectExtension):
AttributeError: 'module' object has no attribute 'EffectExtension'

But when I run Python3 in the terminal inkex has EffectExtension

Python 3.8.10 (default, Sep 28 2021, 16:10:42)
[GCC 9.3.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import inkex
>>> inkex.EffectExtension
<class 'inkex.extensions.EffectExtension'>
>>>

Here are my my_first_extension.inx and my_first_extension.py

<?xml version="1.0" encoding="UTF-8"?>
<inkscape-extension xmlns="http://www.inkscape.org/namespace/inkscape/extension">
  <_name>My First Extension</_name>
  <id>org.inkscape.effect.my_first_extension</id>
  <effect>
    <object-type>all</object-type>
      <effects-menu>
        <submenu _name="TEST"/>
      </effects-menu>
  </effect>
  <script>
    <command reldir="extensions" interpreter="python">my_first_extension.py</command>
  </script>
</inkscape-extension>

import inkex

class MyFirstExtension(inkex.EffectExtension):
    def effect(self):
        for elem in self.svg.get_selected():
            elem.style[fill] = 'red'

o = MyFirstExtension()
o.run()

Any help would be appreciated

Can you replace 

o = MyFirstExtension()
o.run()

with 

if __name__ == '__main__':
    MyFirstExtension().run()

https://gitlab.com/inkscape/extensions/-/wikis/home

switching to

if __name__ == '__main__':
    MyFirstExtension().run()

did not help it. But i am going to try to run the examples from gitlab and see what happens.

In Ubuntu 20.10 with Inkscape 1.1:

This will work:

.inx

<?xml version="1.0" encoding="UTF-8"?>
<inkscape-extension xmlns="http://www.inkscape.org/namespace/inkscape/extension">
  <name>My First Extension</name>
  <id>org.inkscape.effect.my_first_extension</id>
  <effect>
    <object-type>all</object-type>
      <effects-menu>
        <submenu _name="TEST"/>
      </effects-menu>
  </effect>
  <script>
    <command location="inx" interpreter="python">my_first_extension.py</command>
  </script>
</inkscape-extension>

.py

import inkex

class MyFirstExtension(inkex.EffectExtension):
    def effect(self):

        # Get current selection element list
        current_selected = self.svg.selected
        # Make sure at least one object is selected otherwise return
        if len(current_selected) > 0:
            for elem in current_selected:
                elem.style['fill'] = 'red'
        else:
            return

o = MyFirstExtension()
o.run()