Changes to supported evaluation syntax in Python 3

Initial topic - https://groups.google.com/forum/#!topic/robotframework-users/OX5OvCmVwio

For some reasons expression Evaluate [$PAGE_COMPONENTS[k]['name'] for k in $PAGE_COMPONENTS] doesn't work for python 3.7, but works perfectly for python 2.7

Evaluating expression '[RF_VAR_PAGE_COMPONENTS [k ]['name']for k in RF_VAR_PAGE_COMPONENTS ]' failed: NameError: name 'RF_VAR_PAGE_COMPONENTS' is not defined

*** Settings ***
Documentation    Handle nested dicts

Library          Collections

*** Variables ***
&{PAGE_COMPONENTS}         component_one=&{COMPONENT_ONE_PARAMS}
                    ...    component_two=&{COMPONENT_TWO_PARAMS}
&{COMPONENT_ONE_PARAMS}    name=ComponentOne    parameter=ParameterOne
&{COMPONENT_TWO_PARAMS}    name=ComponentTwo    parameter=ParameterTwo

@{EXPECTED_NAMES}          ComponentOne    ComponentTwo

*** Test cases ***
Access To Nested Dict Values In Evaluate Keyword
    ${robot_version} =  Evaluate    robot.version.get_full_version(program=None, naked=False)    modules=robot
   Log    ${robot_version}    level=WARN
   @{component_names} =  Evaluate    [$PAGE_COMPONENTS[k]['name'] for k in $PAGE_COMPONENTS]
   # @{component_names} =  Evaluate    [${PAGE_COMPONENTS}\[k]['name'] for k in $PAGE_COMPONENTS]  -  it works for both versions, but I don't have any idea why the previous line doesn't work
   Log    ${component_names}    level=WARN

   Lists Should Be Equal    ${component_names}    ${EXPECTED_NAMES}

*** Keywords ***

d:\rf_bug_report>robot handle_nested_dicts.robot
==============================================================================
Handle Nested Dicts :: Handle nested dicts
==============================================================================
**[ WARN ] 3.1.2 (Python 2.7.13 on win32)**
[ WARN ] [u'ComponentOne', u'ComponentTwo']
Access To Nested Dict Values In Evaluate Keyword                      | PASS |
------------------------------------------------------------------------------
Handle Nested Dicts :: Handle nested dicts                            | PASS |
1 critical test, 1 passed, 0 failed
1 test total, 1 passed, 0 failed
==============================================================================
Output:  d:\rf_bug_report\output.xml
Log:     d:\rf_bug_report\log.html
Report:  d:\rf_bug_report\report.html

d:\rf_bug_report>robot3 handle_nested_dicts.robot
==============================================================================
Handle Nested Dicts :: Handle nested dicts
==============================================================================
**[ WARN ] 3.1.2 (Python 3.7.3 on win32)**
Access To Nested Dict Values In Evaluate Keyword                      | **FAIL** |
Evaluating expression '[RF_VAR_PAGE_COMPONENTS [k ]['name']for k in  RF_VAR_PAGE_COMPONENTS ]' failed: NameError: name 'RF_VAR_PAGE_COMPONENTS' is not defined
------------------------------------------------------------------------------
Handle Nested Dicts :: Handle nested dicts                            | FAIL |
1 critical test, 0 passed, 1 failed
1 test total, 0 passed, 1 failed
==============================================================================
Output:  d:\rf_bug_report\output.xml
Log:     d:\rf_bug_report\log.html
Report:  d:\rf_bug_report\report.html