1try: 2 import uos as os 3except ImportError: 4 import os 5 6if not hasattr(os, "remove"): 7 print("SKIP") 8 raise SystemExit 9 10# cleanup in case testfile exists 11try: 12 os.remove("testfile") 13except OSError: 14 pass 15 16try: 17 f = open("testfile", "r+b") 18 print("Unexpectedly opened non-existing file") 19except OSError: 20 print("Expected OSError") 21 pass 22 23f = open("testfile", "w+b") 24f.write(b"1234567890") 25f.seek(0) 26print(f.read()) 27f.close() 28 29# Open with truncation 30f = open("testfile", "w+b") 31f.write(b"abcdefg") 32f.seek(0) 33print(f.read()) 34f.close() 35 36# Open without truncation 37f = open("testfile", "r+b") 38f.write(b"1234") 39f.seek(0) 40print(f.read()) 41f.close() 42 43# cleanup 44try: 45 os.remove("testfile") 46except OSError: 47 pass 48