UnComment

import bpy


# Specify the exact file path for your 'defines.hpp' file
#file_path = r"C:\Users\carra\Desktop\volo\FluidX3D\src\defines.hpp"

file_path = "C:/Users/carra/Desktop/BUIFluidX3D/pragmaonce.txt"

ln = bui_fluidx3d['sna_line'] # This is actually referring to the 7th line due to 0-based indexing

# Read the lines from the file
with open(file_path, 'r') as file:
    lines = file.readlines()

# Note: Ensure that the file has enough lines to avoid IndexError
if lines[ln].startswith('//'):
    # Uncomment the line by removing the leading comment markers
    lines[ln] = lines[ln][2:]
else:
    # Comment the line by adding '//' at the beginning if not already commented
    lines[ln] = '//' + lines[ln]

# Write all lines back to the file
with open(file_path, 'w') as file:
    file.writelines(lines)

# Print the modified line for confirmation
print(lines[ln])