TypeError: string indices must be integers, not 'str'

[deanhystad]

Ignoring the database for now, your program cannot work because there is nothing linking the dictionary fr and the string "fr". Contrary to your comment "# default value x = fr, en, es from for i in rows (line 32)" x does not equal fr, en or es. it equals 0, 1 or 2. That is fairly worthless information because there is also no way to get from 0, 1 or 2 to fr, en or es.

Instead of having separate dictionaries for each language, I would have a dictionary of languages.

languages = {
    "en": {
        "_title": "MyTitle",
        "_menu": "MyMenu",
    },
    "fr": {
        "_title": "MonTitre",
        "_menu": "MonMenu",
    },
    "es": {
        "_title": "MiTitulo",
        "_menu": "MiMenú",
    },
}

Now you can use "en" to get the translation dictionary for "en". I use this dictionary in the program below.

import tkinter as tk  # Do not use wildcard imports


languages = {
    "en": {
        "_title": "MyTitle",
        "_menu": "MyMenu",
    },
    "fr": {
        "_title": "MonTitre",
        "_menu": "MonMenu",
    },
    "es": {
        "_title": "MiTitulo",
        "_menu": "MiMenú",
    },
}


def language_changed(*_):
    global language_pack
    lang = language_selection.get()
    language_pack = languages[lang]
    root.title(language_pack["_title"])
    translations.set("\n".join([f"{a}: {b}" for a, b in language_pack.items()]))


language_options = list(languages)
language_pack = languages[language_options[0]]

root = tk.Tk()
language_selection = tk.StringVar(root, language_options[0])
language_selection.trace_add("write", language_changed)
tk.OptionMenu(root, language_selection, *language_options).pack(padx=100, pady=10)

translations = tk.StringVar(root, "")
tk.Label(root, textvariable=translations).pack(padx=100, pady=10)

language_changed()

root.mainloop()

I left the database stuff out because I don't have your database, and it is not related to your current issue. But if I did have a database that I could use to get my translation language choices, I would use it like this:

language_options = [row[0] for row in cursor.execute("SELECT * FROM langPack")]
language = StringVar(root, language_options[0])
w = OptionMenu(root, language, *language_options)