Getting Variable accessing error after upgrading the Python and Robot framework version

Question

Below mentioned script has been worked in old python (2.7.x) and Robotframework version . The same code is not being worked ,after upgrading the python version from 2.7 to 3.7.2 and the robot version to 3.1.1.

I'm getting this error while executing script:

Variable '${var}' is string, not list or dictionary, and thus accessing item '${var}' from it is not possible.

Code :

${loc}   xpath=(//*[contains(@class,"c3-legend-item ")])

: FOR    ${row}    IN RANGE    1        ${Count}
\    ${Exp_Name} =    Get Text    ${loc}[${row}]    
\   Log    ${Exp_Name}

Answer 1

In robot version 3.1 there was a backwards-incompatible change. From the release notes:

Square brackets after variable like ${var}[xxx] is considered item access

Syntax like ${var}[xxx] is now considered variable item access (#2601), not variable ${var} followed by a literal string [xxx]. If the latter is desired, escaping like ${var}[xxx] is needed.

In your specific case you're using ${loc}[${row}], where you're expecting [${row}] to be appended to ${loc}. In 3.1 robot thinks that [${row}] is an index into ${loc}.

The fix, as suggested in the release notes, is to escape the opening square bracket:

\    ${Exp_Name} =    Get Text    ${loc}\[${row}]

Answer 2

Use catenate to build dynamic xpath. This will work for you.

${loc}   xpath=(//*[contains(@class,"c3-legend-item ")])

: FOR    ${row}    IN RANGE    1        ${Count}

\    ${dynamic_xpath}=    Catenate    SEPARATOR=    ${loc}    [${row}]

\    ${Exp_Name} =    Get Text    ${dynamic_xpath}