Visit regular imports.

def visit_Import(self, node, frame):
        """Visit regular imports."""
        if node.with_context:
            self.unoptimize_scope(frame)
        self.writeline('l_%s = ' % node.target, node)
        if frame.toplevel:
            self.write('context.vars[%r] = ' % node.target)
        self.write('environment.get_template(')
        self.visit(node.template, frame)
        self.write(', %r).' % self.name)
        if node.with_context:
            self.write('make_module(context.parent, True, locals())')
        else:
            self.write('module')
        if frame.toplevel and not node.target.startswith('_'):
            self.writeline('context.exported_vars.discard(%r)' % node.target)
        frame.assigned_names.add(node.target)