zsh: external-argcomplete-script does not work on register-python-argcomplete about argcomplete HOT 2 CLOSED

alias scmd1='script.py cmd1'
alias scmd1='script.py cmd1'
...
alias scmdn='script.py cmdN'

# $1 - alias name
# $2 - target commands
__gen_completion_func() {
    eval "
    __completion_$1()
    {
        local _alias=$1
        local aliaslen=\${#_alias}
        local realcmd=\"$2\"
        local realcmdlen=\${#realcmd}
        COMP_POINT=\$(expr \$COMP_POINT - \$aliaslen + \$realcmdlen)
        COMP_LINE=\"\${realcmd}\${COMP_LINE:\$aliaslen}\"

        script.py
    }"

    eval "$(register-python-argcomplete -e __completion_$1 $1)"
}

# and call it:
__gen_completion_func scmd1  "script.py cmd1"
__gen_completion_func scmd2  "script.py cmd2"
...

kcd() {
    dir=$(script.py dir $1) && cd $dir;
}

# and use previous function to generate completion:
__gen_completion_func kcd  "script.py dir"