Run function, variable argument empty value

I hope you can help me.

I’m using run function from a python file to execute a test suite, I’m trying to pass a variable as argument but when I try to read it from the test suite I get an empty value, what am I doing wrong?
from robot import run
run(‘test_suite.robot’, variable={‘variable1’: ‘value1’})

*** Variables ***
${variable1} value0
*** Test Cases ***
Test Case 1
Log ${variable1}

If I use run function without variable argument, Log ${variable1} returns value0 as expected but if I use it with variable argumente I get empty value.

Thank you for your help