font_size = 14
font_family = "Arial"
style1 = "font-size: {0};font-family: \"{1}\"".format(
font_size, font_family)
# style1 is 'font-size: 14;font-family: "Arial"'
# Since 3.6: f-string, any expression inside
style2 = f"font-size: {font_size/2};font-family: \"{font_family}\""
# style2 is 'font-size: 7.0;font-family: "Arial"'
# Since 3.8: "=" adds the expression text
style3 = f"{font_size = }"
# style3 is 'font_size = 14'
# Trap: without the f prefix nothing is substituted
plain = "font-size: {font_size}"
# plain is 'font-size: {font_size}'
print(f"{style1 = }")
print(f"{style2 = }")
print(f"{style3 = }")
print(f"{plain = }")