My question is if there is a way to put in a single ttk.label() a text that show the full text with only some words in the bold font like this. I am doing this right now applying styles to many ttk.labels(), but this method imply that I must position every label next to the other, and that the program is multilingual, some strings don't fit correctly with the window. If there is a way to do this, it will be a great advantage to my work. Thanks.
No, you cannot change the attributes of only some of the characters in a Label widget. If you need to style individual character you need to use a small Text widget.
For example:
text = tk.Text(root, height=1, font="Helvetica 12")
text.tag_configure("bold", font="Helvetica 12 bold")
text.insert("end", "Hello, ")
text.insert("end", "world", "bold")
text.configure(state="disabled")
来源：https://stackoverflow.com/questions/40237671/python-tkinter-single-label-with-bold-and-normal-text