{!> ../../docs_src/security/tutorial004.py!}
```

////

## Update the dependencies

Update `get_current_user` to receive the same token as before, but this time, using JWT tokens.

Decode the received token, verify it, and return the current user.

If the token is invalid, return an HTTP error right away.

//// tab | Python 3.10+

```Python hl_lines="90-107"

```

////

## Die Abhängigkeiten aktualisieren

Aktualisieren Sie `get_current_user`, um den gleichen Token wie zuvor zu erhalten, dieses Mal jedoch unter Verwendung von JWT-Tokens.

Dekodieren Sie den empfangenen Token, validieren Sie ihn und geben Sie den aktuellen Benutzer zurück.

Wenn der Token ungültig ist, geben Sie sofort einen HTTP-Fehler zurück.

//// tab | Python 3.10+

```Python hl_lines="89-106"

	var tokens []Token
	for _, tok := range macro.tokens {
		if tok.ScanToken != scanner.Ident {
			tokens = append(tokens, tok)
			continue
		}
		substitution := actuals[tok.text]
		if substitution == nil {
			tokens = append(tokens, tok)
			continue
		}
		tokens = append(tokens, substitution...)
	}
	in.Push(NewSlice(in.Base(), in.Line(), tokens))
}

	Close()
}

// A Token is a scan token plus its string value.
// A macro is stored as a sequence of Tokens with spaces stripped.
type Token struct {
	ScanToken
	text string
}

// Make returns a Token with the given rune (ScanToken) and text representation.
func Make(token ScanToken, text string) Token {
	// Substitute the substitutes for . and /.
	text = strings.ReplaceAll(text, "\u00B7", ".")

Xiaopeng Han <******@****.***> 1686841337 +0800

		},
	},
}

func mainHandler(w http.ResponseWriter, r *http.Request) {
	token := r.FormValue("token")
	if token == "" {
		writeErrorResponse(w, errors.New("token parameter not given"))
		return
	}

	rsp, ok := tokens[token]
	if !ok {
		w.WriteHeader(http.StatusForbidden)
		return
	}

	fmt.Printf("Allowed for token: %s user: %s\n", token, rsp.User)

	w.WriteHeader(http.StatusOK)
	json.NewEncoder(w).Encode(rsp)

Xiaopeng Han <******@****.***> 1686841337 +0800

Xiaopeng Han <******@****.***> 1686841337 +0800

	// Create a custom split function by wrapping the existing ScanWords function.
	split := func(data []byte, atEOF bool) (advance int, token []byte, err error) {
		advance, token, err = bufio.ScanWords(data, atEOF)
		if err == nil && token != nil {
			_, err = strconv.ParseInt(string(token), 10, 32)
		}
		return
	}
	// Set the split function for the scanning operation.
	scanner.Split(split)
	// Validate the input

		if s.end > s.start || s.err != nil {
			advance, token, err := s.split(s.buf[s.start:s.end], s.err != nil)
			if err != nil {
				if err == ErrFinalToken {
					s.token = token
					s.done = true
					// When token is not nil, it means the scanning stops
					// with a trailing token, and thus the return value
					// should be true to indicate the existence of the token.
					return token != nil