Customized Ctags syntax for parsing R and Pandas data frame columns

gistfile1.txt

# put the following under ~/.ctags.d/options.ctags, don't include this line into ~/.ctags.d/options.ctags

--langdef=Rext{base=R}
--kinddef-Rext=v,variable,a variable with named attr
--kinddef-Rext=n,nameattr,the named attributes of a variable
--_roledef-Rext.v=nondefinition,this is not a definition

--regex-Rext=/([[:alnum:]_.]+)\$[[:alnum:]_.]+\s*(<-|=)[^=]/\1/v/{scope=push}{_role=nondefinition}
--regex-Rext=/[[:alnum:]_.]+\$([[:alnum:]_.]+)\s*(<-|=)[^=]/\1/n/{scope=ref}
--regex-Rext=/[[:alnum:]_.]+\$[[:alnum:]_.]+\s*(<-|=)[^=].*///{scope=pop}{placeholder}

--regex-Rext=/([[:alnum:]_.]+)\$`.+`\s*(<-|=)[^=]/\1/v/{scope=push}{_role=nondefinition}
--regex-Rext=/[[:alnum:]_.]+\$(`.+`)\s*(<-|=)[^=]/\1/n/{scope=ref}
--regex-Rext=/[[:alnum:]_.]+\$`.+`\s*(<-|=)[^=].*///{scope=pop}{placeholder}

--regex-Rext=/([[:alnum:]_.]+)\[\[["'].+["']\]\]\s*(<-|=)[^=]/\1/v/{scope=push}{_role=nondefinition}
--regex-Rext=/[[:alnum:]_.]+\[\[["'](.+)["']\]\]\s*(<-|=)[^=]/\1/n/{scope=ref}
--regex-Rext=/[[:alnum:]_.]+\[\[["'].+["']\]\]\s*(<-|=)[^=].*///{scope=pop}{placeholder}

--langdef=Pyext{base=python}
--kinddef-Pyext=v,variable,a variable with named attr
--kinddef-Pyext=n,nameattr,the named attributes of a variable
--_roledef-Pyext.v=nondefinition,this is not a definition

--regex-Pyext=/([[:alnum:]_]+)\[["'].+["']\]\s*=[^=]/\1/v/{scope=push}{_role=nondefinition}
--regex-Pyext=/[[:alnum:]_]+\[["'](.+)["']\]\s*=[^=]/\1/n/{scope=ref}
--regex-Pyext=/[[:alnum:]_]+\[["'].+["']\]\s*=[^=].*///{scope=pop}{placeholder}