Tkinter font not changing on python 3.6.8 on Ubuntu 18.04

Question

I am not able to change the font family of the label in tkinter.

I have written the code to explain the issue. I have also attached a link to show the output. (for images please go to this link I have posted the same question here. https://stackoverflow.com/questions/54170918/tkinter-font-not-changing-on-python-3-6-8-ubuntu-18-04lts?noredirect=1#comment95171516_54170918)

from tkinter import *
from tkinter import ttk

win = Tk()
win.title("Fonts not Changing!")
win.geometry("400x400")

# Times label
label1 = ttk.Label(win, text = "Brown-Times", font = ("Times",15))
label1.grid(row = 0, column = 0, sticky = 'W')

label12 = ttk.Label(win, text = "Brown-times", font = ("times",15))
label12.grid(row = 0, column = 1, sticky = 'W')

# Arial label
label2 = ttk.Label(win, text = "Brown-Arial", font = ("Arial",15))
label2.grid(row = 1, column = 0, sticky = 'W')

label22 = ttk.Label(win, text = "Brown-arial", font = ("arial",15))
label22.grid(row = 1, column = 1, sticky = 'W')

# Courier label
label3 = ttk.Label(win, text = "Brown-courier", font = ("courier",15))
label3.grid(row = 2, column = 0, sticky = 'W')
# Helvetica label
label4 = ttk.Label(win, text = "Brown-Helvetica", font = ("Helvetica",15))
label4.grid(row = 3, column = 0, sticky = 'W')

win.mainloop()

^{Image of the output}

I tried with the font families present

from tkinter import *  
from tkinter import ttk  

win = Tk()
win.title("Fonts not Changing!")
win.geometry("400x400")

'''
'fangsong ti', 'fixed', 'clearlyu alternate glyphs', 'courier 10 pitch', 'open look glyph', 'bitstream charter', 'song ti', 'open look cursor', 'newspaper', 'clearlyu ligature', 'mincho', 'clearlyu devangari extra', 'clearlyu pua', 'clearlyu', 'clean', 'nil', 'clearlyu arabic', 'clearlyu devanagari', 'gothic', 'clearlyu arabic extra'
'''

# Times label
label1 = ttk.Label(win, text = "Brown-fangsong ti", font = ("fangsong ti",15))
label1.grid(row = 0, column = 0, sticky = 'W')

label12 = ttk.Label(win, text = "Brown-fixed", font = ("fixed",15))
label12.grid(row = 0, column = 1, sticky = 'W')

# Arial label
label2 = ttk.Label(win, text = "Brown-courier", font = ("courier",15))
label2.grid(row = 1, column = 0, sticky = 'W')

label22 = ttk.Label(win, text = "Brown-clearlyu pua", font = ("clearlyu pua",15))
label22.grid(row = 1, column = 1, sticky = 'W')

# Courier label
label3 = ttk.Label(win, text = "Brown-courier", font = ("courier",15))
label3.grid(row = 2, column = 0, sticky = 'W')
# Helvetica label
label4 = ttk.Label(win, text = "Brown-Helvetica", font = ("Helvetica",15))
label4.grid(row = 3, column = 0, sticky = 'W')

win.mainloop()

but the output is similar.

I have tried with all the basic fonts available with tcl code as well as Python. Please look at the difference.

TCL code

#!/usr/bin/wish

font create myFont1 -family {fangsong ti} -size 18 -weight bold
pack [label .labelVar1 -font myFont1 -text "Hello World"]

font create myFont2 -family fixed -size 18 -weight bold
pack [label .labelVar2 -font myFont2 -text "Hello World"]

font create myFont3 -family {clearlyu alternate glyphs} -size 18 -weight bold
pack [label .labelVar3 -font myFont3 -text "Hello World"]

font create myFont4 -family {courier 10 pitch} -size 18 -weight bold
pack [label .labelVar4 -font myFont4 -text "Hello World"]

font create myFont5 -family {open look glyph} -size 18 -weight bold
pack [label .labelVar5 -font myFont5 -text "Hello World"]

font create myFont6 -family {bitstream charter} -size 18 -weight bold
pack [label .labelVar6 -font myFont6 -text "Hello World"]

font create myFont7 -family {song ti} -size 18 -weight bold
pack [label .labelVar7 -font myFont7 -text "Hello World"]

font create myFont8 -family {open look cursor} -size 18 -weight bold
pack [label .labelVar8 -font myFont8 -text "Hello World"]

font create myFont9 -family newspaper -size 18 -weight bold
pack [label .labelVar9 -font myFont9 -text "Hello World"]

font create myFont10 -family {clearlyu ligature} -size 18 -weight bold
pack [label .labelVar10 -font myFont10 -text "Hello World"]

font create myFont11 -family mincho -size 18 -weight bold
pack [label .labelVar11 -font myFont11 -text "Hello World"]

font create myFont12 -family {clearlyu devangari extra} -size 18 -weight bold
pack [label .labelVar12 -font myFont12 -text "Hello World"]

font create myFont13 -family {clearlyu pua} -size 18 -weight bold
pack [label .labelVar13 -font myFont13 -text "Hello World"]

font create myFont14 -family clearlyu -size 18 -weight bold
pack [label .labelVar14 -font myFont14 -text "Hello World"]

font create myFont15 -family clean -size 18 -weight bold
pack [label .labelVar15 -font myFont15 -text "Hello World"]

font create myFont16 -family nil -size 18 -weight bold
pack [label .labelVar16 -font myFont16 -text "Hello World"]

font create myFont17 -family {clearlyu arabic} -size 18 -weight bold
pack [label .labelVar17 -font myFont17 -text "Hello World"]

font create myFont18 -family {clearlyu devanagari} -size 18 -weight bold
pack [label .labelVar18 -font myFont18 -text "Hello World"]

font create myFont19 -family gothic -size 18 -weight bold
pack [label .labelVar19 -font myFont19 -text "Hello World"]

font create myFont20 -family {clearlyu arabic extra} -size 18 -weight bold
pack [label .labelVar20 -font myFont20 -text "Hello World"]

puts [font families]  

Python code

from tkinter import *
from tkinter import ttk

win = Tk()
win.title("Fonts not Changing!")
win.geometry("400x400")

fontList = ["{fangsong ti}", "fixed", "{clearlyu alternate glyphs}", "{courier 10 pitch}", "{open look glyph}", "{bitstream charter}", "{song ti}", "{open look cursor}", "newspaper", "{clearlyu ligature}", "mincho", "{clearlyu devangari extra}", "{clearlyu pua}", "clearlyu", "clean", "nil", "{clearlyu arabic}", "{clearlyu devanagari}", "gothic", "{clearlyu arabic extra}"]

label = [ttk.Label(win) for i in range(0,len(fontList))]

for i in range(0,len(fontList)):
    label[i].config(text = "Brown-" + fontList[i], font = (fontList[i],18,"bold"))
    label[i].grid(row = i, column = 0, sticky = 'W')

win.mainloop()

When these same fonts are ran using Python it's acting weirdly. As you can see how most of the fonts which were looking different using TCL codes are becoming the same font with Python (even though some fonts change).

I also removed tcl/tk and reinstalled (8.6 version) them. Even then it's of no use. Or is there any way that I can add more fonts to the tcl/tk?