f = open(r'c:\text\somefile.txt', 'w')f.write('01234567890123456789')f.seek(5)f.write('Hello, World!')f.close()f = open(r'c:\text\somefile.txt')print f.read()f = open(r'c:\text\somefile.txt')print f.read(3)print f.read(2)print f.tell()