Lib/test/test_file.py

   1 import sys
   2 import os
   3 from array import array
   4 from weakref import proxy
   5
   6 from test.test_support import verify, TESTFN, TestFailed
   7 from UserList import UserList
   8
   9 # verify weak references
  10 f = file(TESTFN, 'w')
  11 p = proxy(f)
  12 p.write('teststring')
  13 verify(f.tell(), p.tell())
  14 f.close()
  15 f = None
  16 try:
  17     p.tell()
  18 except ReferenceError:
  19     pass
  20 else:
  21     raise TestFailed('file proxy still exists when the file is gone')
  22
  23 # verify expected attributes exist
  24 f = file(TESTFN, 'w')
  25 softspace = f.softspace
  26 f.name     # merely shouldn't blow up
  27 f.mode     # ditto
  28 f.closed   # ditto
  29
  30 # verify softspace is writable
  31 f.softspace = softspace    # merely shouldn't blow up
  32
  33 # verify the others aren't
  34 for attr in 'name', 'mode', 'closed':
  35     try:
  36         setattr(f, attr, 'oops')
  37     except (AttributeError, TypeError):
  38         pass
  39     else:
  40         raise TestFailed('expected exception setting file attr %r' % attr)
  41 f.close()
  42
  43 # check invalid mode strings
  44 for mode in ("", "aU", "wU+"):
  45     try:
  46         f = file(TESTFN, mode)
  47     except ValueError:
  48         pass
  49     else:
  50         f.close()
  51         raise TestFailed('%r is an invalid file mode' % mode)
  52
  53 # verify writelines with instance sequence
  54 l = UserList(['1', '2'])
  55 f = open(TESTFN, 'wb')
  56 f.writelines(l)
  57 f.close()
  58 f = open(TESTFN, 'rb')
  59 buf = f.read()
  60 f.close()
  61 verify(buf == '12')
  62
  63 # verify readinto
  64 a = array('c', 'x'*10)
  65 f = open(TESTFN, 'rb')
  66 n = f.readinto(a)
  67 f.close()
  68 verify(buf == a.tostring()[:n])
  69
  70 # verify writelines with integers
  71 f = open(TESTFN, 'wb')
  72 try:
  73     f.writelines([1, 2, 3])
  74 except TypeError:
  75     pass
  76 else:
  77     print "writelines accepted sequence of integers"
  78 f.close()
  79
  80 # verify writelines with integers in UserList
  81 f = open(TESTFN, 'wb')
  82 l = UserList([1,2,3])
  83 try:
  84     f.writelines(l)
  85 except TypeError:
  86     pass
  87 else:
  88     print "writelines accepted sequence of integers"
  89 f.close()
  90
  91 # verify writelines with non-string object
  92 class NonString: pass
  93
  94 f = open(TESTFN, 'wb')
  95 try:
  96     f.writelines([NonString(), NonString()])
  97 except TypeError:
  98     pass
  99 else:
 100     print "writelines accepted sequence of non-string objects"
 101 f.close()
 102
 103 try:
 104     sys.stdin.seek(-1)
 105 except IOError:
 106     pass
 107 else:
 108     print "should not be able to seek on sys.stdin"
 109
 110 try:
 111     sys.stdin.truncate()
 112 except IOError:
 113     pass
 114 else:
 115     print "should not be able to truncate on sys.stdin"
 116
 117 # verify repr works
 118 f = open(TESTFN)
 119 if not repr(f).startswith("<open file '" + TESTFN):
 120     print "repr(file) failed"
 121 f.close()
 122
 123 # verify repr works for unicode too
 124 f = open(unicode(TESTFN))
 125 if not repr(f).startswith("<open file u'" + TESTFN):
 126     print "repr(file with unicode name) failed"
 127 f.close()
 128
 129 # verify that we get a sensible error message for bad mode argument
 130 bad_mode = "qwerty"
 131 try:
 132     open(TESTFN, bad_mode)
 133 except IOError, msg:
 134     if msg[0] != 0:
 135         s = str(msg)
 136         if s.find(TESTFN) != -1 or s.find(bad_mode) == -1:
 137             print "bad error message for invalid mode: %s" % s
 138     # if msg[0] == 0, we're probably on Windows where there may be
 139     # no obvious way to discover why open() failed.
 140 else:
 141     print "no error for invalid mode: %s" % bad_mode
 142
 143 f = open(TESTFN)
 144 if f.name != TESTFN:
 145     raise TestFailed, 'file.name should be "%s"' % TESTFN
 146 if f.isatty():
 147     raise TestFailed, 'file.isatty() should be false'
 148
 149 if f.closed:
 150     raise TestFailed, 'file.closed should be false'
 151
 152 try:
 153     f.readinto("")
 154 except TypeError:
 155     pass
 156 else:
 157     raise TestFailed, 'file.readinto("") should raise a TypeError'
 158
 159 f.close()
 160 if not f.closed:
 161     raise TestFailed, 'file.closed should be true'
 162
 163 # make sure that explicitly setting the buffer size doesn't cause
 164 # misbehaviour especially with repeated close() calls
 165 for s in (-1, 0, 1, 512):
 166     try:
 167         f = open(TESTFN, 'w', s)
 168         f.write(str(s))
 169         f.close()
 170         f.close()
 171         f = open(TESTFN, 'r', s)
 172         d = int(f.read())
 173         f.close()
 174         f.close()
 175     except IOError, msg:
 176         raise TestFailed, 'error setting buffer size %d: %s' % (s, str(msg))
 177     if d != s:
 178         raise TestFailed, 'readback failure using buffer size %d'
 179
 180 methods = ['fileno', 'flush', 'isatty', 'next', 'read', 'readinto',
 181            'readline', 'readlines', 'seek', 'tell', 'truncate', 'write',
 182            'xreadlines', '__iter__']
 183 if sys.platform.startswith('atheos'):
 184     methods.remove('truncate')
 185
 186 for methodname in methods:
 187     method = getattr(f, methodname)
 188     try:
 189         method()
 190     except ValueError:
 191         pass
 192     else:
 193         raise TestFailed, 'file.%s() on a closed file should raise a ValueError' % methodname
 194
 195 try:
 196     f.writelines([])
 197 except ValueError:
 198     pass
 199 else:
 200     raise TestFailed, 'file.writelines([]) on a closed file should raise a ValueError'
 201
 202 os.unlink(TESTFN)
 203
 204 def bug801631():
 205     # SF bug <http://www.python.org/sf/801631>
 206     # "file.truncate fault on windows"
 207     f = file(TESTFN, 'wb')
 208     f.write('12345678901')   # 11 bytes
 209     f.close()
 210
 211     f = file(TESTFN,'rb+')
 212     data = f.read(5)
 213     if data != '12345':
 214         raise TestFailed("Read on file opened for update failed %r" % data)
 215     if f.tell() != 5:
 216         raise TestFailed("File pos after read wrong %d" % f.tell())
 217
 218     f.truncate()
 219     if f.tell() != 5:
 220         raise TestFailed("File pos after ftruncate wrong %d" % f.tell())
 221
 222     f.close()
 223     size = os.path.getsize(TESTFN)
 224     if size != 5:
 225         raise TestFailed("File size after ftruncate wrong %d" % size)
 226
 227 try:
 228     bug801631()
 229 finally:
 230     os.unlink(TESTFN)