The variable is defined through the global statement but no assignment to this variable is done. It is recommended to remove it if not necessary.

Bad practice

def my_func():
    global a
    return a

Recommended

If it is a newly defined global, make sure to assign a value to it.

def my_func():
    global a
    a = 1    # Assign to the newly defined global value.
    return a

Or if the global should be already defined, you can remove the global statement.

a = 1

def my_func():
    return a  # The global statement can be removed

Note: DeepSource will remove the global statement during autofix.