import sys try: import uos as os except ImportError: import os if not hasattr(os, "unlink"): print("SKIP") sys.exit() # cleanup in case testfile exists try: os.unlink("testfile") except OSError: pass try: f = open("testfile", "r+b") print("Unexpectedly opened non-existing file") except OSError: print("Expected OSError") pass f = open("testfile", "w+b") f.write(b"1234567890") f.seek(0) print(f.read()) f.close() # Open with truncation f = open("testfile", "w+b") f.write(b"abcdefg") f.seek(0) print(f.read()) f.close() # Open without truncation f = open("testfile", "r+b") f.write(b"1234") f.seek(0) print(f.read()) f.close()