Changed a string substitution to os.path.join

Author: asenyaev

setup.py

@@ -366,15 +366,13 @@ def _classify_installed_files_override(
         print("Copying files from CMake output")
 
         # lines for a proper work using pylint and an autocomplete in IDE
-        with open("%spython/cv2/__init__.py"
-        % cmake_install_dir, 'r') as opencv_init:
+        with open(os.path.join(cmake_install_dir, "python", "cv2", "__init__.py"), 'r') as opencv_init:
             opencv_init_lines = opencv_init.readlines()
             extra_imports = ('\nfrom .cv2 import *\nfrom . import data\n')
             free_line_after_imports = 5
             opencv_init_lines.insert(free_line_after_imports, extra_imports)
 
-        with open("%spython/cv2/__init__.py"
-        % cmake_install_dir, 'w') as opencv_final_init:
+        with open(os.path.join(cmake_install_dir, "python", "cv2", "__init__.py"), 'w') as opencv_final_init:
             opencv_final_init.writelines(opencv_init_lines)
 
         # add lines from the old __init__.py file to the config file