diff --git a/_xtool/pydump/pydump.go b/_xtool/pydump/pydump.go
index dd44292..7b8be43 100644
--- a/_xtool/pydump/pydump.go
+++ b/_xtool/pydump/pydump.go
@@ -1,28 +1,16 @@
 package main
 
 import (
-	"encoding/json"
+	"os"
 	"fmt"
+	"strings"
+	"encoding/json"
 	"github.com/goplus/lib/c"
 	"github.com/goplus/lib/py"
 	"github.com/goplus/lib/py/inspect"
-	"os"
-	"strings"
+	"github.com/goplus/llpyg/symbol"
 )
 
-type symbol struct {
-	Name string `json:"name"`
-	Type string `json:"type"`
-	Doc  string `json:"doc"`
-	Sig  string `json:"sig"`
-}
-
-type module struct {
-	Name      string    `json:"name"`      // python module name
-	Functions []*symbol `json:"functions"` // package functions
-	// TODO: variables, classes, etc.
-}
-
 var pyFuncTypes = map[string]bool{
 	"ufunc":                      true,
 	"method":                     true,
@@ -50,7 +38,7 @@ func extractSignatureFromDoc(doc, funcName string) string {
 	return strings.Join(fields, " ")
 }
 
-func getSignature(val *py.Object, sym *symbol) string {
+func getSignature(val *py.Object, sym *symbol.Symbol) string {
 	// function, method, class, or implement __call__
 	if val.Callable() == 0 {
 		return ""
@@ -76,7 +64,7 @@ func getSignature(val *py.Object, sym *symbol) string {
 }
 
 // moduleName: Python module name
-func pydump(moduleName string) (*module, error) {
+func pydump(moduleName string) (*symbol.Module, error) {
 	// import module
 	mod := py.ImportModule(c.AllocaCStr(moduleName))
 	if mod == nil {
@@ -88,7 +76,7 @@ func pydump(moduleName string) (*module, error) {
 		return nil, fmt.Errorf("failed to get dict keys of %s", moduleName)
 	}
 	// create module instance
-	modInstance := &module{
+	modInstance := &symbol.Module{
 		Name: moduleName,
 	}
 	// get symbols
@@ -99,7 +87,7 @@ func pydump(moduleName string) (*module, error) {
 			continue
 		}
 		// define symbol
-		sym := &symbol{}
+		sym := &symbol.Symbol{}
 		sym.Name = c.GoString(key.CStr())
 		sym.Type = c.GoString(val.Type().TypeName().CStr())
 		doc := val.GetAttrString(c.Str("__doc__"))
diff --git a/tool/pygen/symbol.go b/symbol/symbol.go
similarity index 63%
rename from tool/pygen/symbol.go
rename to symbol/symbol.go
index 8dc30ca..e0e5d2b 100644
--- a/tool/pygen/symbol.go
+++ b/symbol/symbol.go
@@ -1,14 +1,14 @@
-package pygen
+package symbol
 
-type symbol struct {
+type Symbol struct {
 	Name string `json:"name"`
 	Type string `json:"type"`
 	Doc  string `json:"doc"`
 	Sig  string `json:"sig"`
 }
 
-type module struct {
+type Module struct {
 	Name      string    `json:"name"`      // python module name
-	Functions []*symbol `json:"functions"` // package functions
+	Functions []*Symbol `json:"functions"` // package functions
 	// TODO: variables, classes, etc.
 }
diff --git a/tool/pygen/genfunc.go b/tool/pygen/genfunc.go
index 3176f74..9474b7d 100644
--- a/tool/pygen/genfunc.go
+++ b/tool/pygen/genfunc.go
@@ -1,13 +1,14 @@
 package pygen
 
 import (
-	"github.com/goplus/gogen"
 	"go/ast"
 	"go/token"
 	"go/types"
+	"github.com/goplus/gogen"
+	"github.com/goplus/llpyg/symbol"
 )
 
-func (ctx *context) genFunc(pkg *gogen.Package, sym *symbol) {
+func (ctx *context) genFunc(pkg *gogen.Package, sym *symbol.Symbol) {
 	name, symSig := sym.Name, sym.Sig
 	if len(name) == 0 || name[0] == '_' {
 		return
@@ -30,6 +31,6 @@ func (ctx *context) genFunc(pkg *gogen.Package, sym *symbol) {
 	fn.SetComments(pkg, &ast.CommentGroup{List: docList})
 }
 
-func (ctx *context) genLinkname(name string, sym *symbol) *ast.Comment {
+func (ctx *context) genLinkname(name string, sym *symbol.Symbol) *ast.Comment {
 	return &ast.Comment{Text: "//go:linkname " + name + " py." + sym.Name}
 }
diff --git a/tool/pygen/pygen.go b/tool/pygen/pygen.go
index 3615f55..905398d 100644
--- a/tool/pygen/pygen.go
+++ b/tool/pygen/pygen.go
@@ -14,6 +14,7 @@ import (
 	"go/types"
 	"github.com/goplus/gogen"
 	"github.com/goplus/llpyg/tool/pysig"
+	"github.com/goplus/llpyg/symbol"
 )
 
 
@@ -23,7 +24,7 @@ type context struct {
 	objPtr *types.Pointer
 	ret    *types.Tuple
 	py     gogen.PkgRef
-	skips  []symbol
+	skips  []symbol.Symbol
 }
 
 
@@ -50,7 +51,7 @@ func GenLLGoBindings(moduleName string, outFile io.Writer) {
 	ctx.pkg.WriteTo(outFile)
 }
 
-func pydump(moduleName string) (mod module, err error) {
+func pydump(moduleName string) (mod symbol.Module, err error) {
 	var out bytes.Buffer
 	cmd := exec.Command("pydump", moduleName)
 	cmd.Stdout = &out
@@ -69,7 +70,7 @@ func pydump(moduleName string) (mod module, err error) {
 	return mod, nil
 }
 
-func createGoPackage(mod module) (ctx *context) {
+func createGoPackage(mod symbol.Module) (ctx *context) {
 	parts := strings.Split(mod.Name, ".")
 	pkgName := parts[len(parts)-1]
 	if goKeywords[pkgName] {
@@ -92,7 +93,7 @@ func createGoPackage(mod module) (ctx *context) {
 	return ctx
 }
 
-func (ctx *context) genMod(pkg *gogen.Package, mod *module) {
+func (ctx *context) genMod(pkg *gogen.Package, mod *symbol.Module) {
 	// global functions
 	funcMap := make(map[string]bool)
 	for _, sym := range mod.Functions {