模板代码出错。错误：

customtkinter.set_appearance_mode("System")  # Modes: system (default), light, dark
AttributeError: module 'customtkinter' has no attribute 'set_appearance_mode'

编码：

import customtkinter

customtkinter.set_appearance_mode("System")  # Modes: system (default), light, dark
customtkinter.set_default_color_theme("blue")  # Themes: blue (default), dark-blue, green

app = customtkinter.CTk()  # create CTk window like you do with the Tk window
app.geometry("400x240")

def button_function():
    print("button pressed")

# Use CTkButton instead of tkinter Button
button = customtkinter.CTkButton(master=app, text="CTkButton", command=button_function)
button.place(relx=0.5, rely=0.5, anchor=customtkinter.CENTER)

app.mainloop()

我在PyCharm中使用了python 3.7版。