coma separator is printed on a new line for some reason

[DeaD_EyE]

I guess prod has at the end of the str a newline character.
You can strip it. I often use rstrip to remove only on the right side of the str whitespace. A newline character is also seen as a whitespace.

delimiter = ","
product_name = "Test 123"
product_name_newline = "Test 123\n"



print("Test without newline")
print(f"{product_name}{delimiter}")
print()

print("Test with newline at the end of the str")
print(f"{product_name_newline}{delimiter}")
print()

print("Test with newline at the end of the str and the prevention")
print(f"{product_name_newline.rstrip()}{delimiter}")
print()