cpython/Lib/test/test_file.py

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2002-06-11 03:22:31 -03:00
import sys
import os
from array import array
from weakref import proxy
from test.test_support import verify, TESTFN, TestFailed, findfile
from UserList import UserList
# verify weak references
f = file(TESTFN, 'w')
p = proxy(f)
p.write('teststring')
verify(f.tell(), p.tell())
f.close()
f = None
try:
p.tell()
except ReferenceError:
pass
else:
raise TestFailed('file proxy still exists when the file is gone')
# verify expected attributes exist
f = file(TESTFN, 'w')
softspace = f.softspace
f.name # merely shouldn't blow up
f.mode # ditto
f.closed # ditto
# verify softspace is writable
f.softspace = softspace # merely shouldn't blow up
# verify the others aren't
for attr in 'name', 'mode', 'closed':
try:
setattr(f, attr, 'oops')
except (AttributeError, TypeError):
pass
else:
raise TestFailed('expected exception setting file attr %r' % attr)
f.close()
# check invalid mode strings
for mode in ("", "aU", "wU+"):
try:
f = file(TESTFN, mode)
except ValueError:
pass
else:
f.close()
raise TestFailed('%r is an invalid file mode' % mode)
# verify writelines with instance sequence
l = UserList(['1', '2'])
f = open(TESTFN, 'wb')
f.writelines(l)
f.close()
f = open(TESTFN, 'rb')
buf = f.read()
f.close()
verify(buf == '12')
# verify readinto
a = array('c', 'x'*10)
f = open(TESTFN, 'rb')
n = f.readinto(a)
f.close()
verify(buf == a.tostring()[:n])
# verify writelines with integers
f = open(TESTFN, 'wb')
try:
f.writelines([1, 2, 3])
except TypeError:
pass
else:
print "writelines accepted sequence of integers"
f.close()
# verify writelines with integers in UserList
f = open(TESTFN, 'wb')
l = UserList([1,2,3])
try:
f.writelines(l)
except TypeError:
pass
else:
print "writelines accepted sequence of integers"
f.close()
# verify writelines with non-string object
class NonString: pass
f = open(TESTFN, 'wb')
try:
f.writelines([NonString(), NonString()])
except TypeError:
pass
else:
print "writelines accepted sequence of non-string objects"
f.close()
try:
sys.stdin.seek(-1)
except IOError:
pass
else:
print "should not be able to seek on sys.stdin"
try:
sys.stdin.truncate()
except IOError:
pass
else:
print "should not be able to truncate on sys.stdin"
# verify repr works
f = open(TESTFN)
if not repr(f).startswith("<open file '" + TESTFN):
print "repr(file) failed"
f.close()
# verify repr works for unicode too
f = open(unicode(TESTFN))
if not repr(f).startswith("<open file u'" + TESTFN):
print "repr(file with unicode name) failed"
f.close()
# verify that we get a sensible error message for bad mode argument
bad_mode = "qwerty"
try:
open(TESTFN, bad_mode)
except IOError, msg:
if msg[0] != 0:
s = str(msg)
if s.find(TESTFN) != -1 or s.find(bad_mode) == -1:
print "bad error message for invalid mode: %s" % s
# if msg[0] == 0, we're probably on Windows where there may be
# no obvious way to discover why open() failed.
else:
print "no error for invalid mode: %s" % bad_mode
f = open(TESTFN)
if f.name != TESTFN:
raise TestFailed, 'file.name should be "%s"' % TESTFN
if f.isatty():
raise TestFailed, 'file.isatty() should be false'
if f.closed:
raise TestFailed, 'file.closed should be false'
try:
f.readinto("")
except TypeError:
pass
else:
raise TestFailed, 'file.readinto("") should raise a TypeError'
f.close()
if not f.closed:
raise TestFailed, 'file.closed should be true'
# make sure that explicitly setting the buffer size doesn't cause
# misbehaviour especially with repeated close() calls
for s in (-1, 0, 1, 512):
try:
f = open(TESTFN, 'w', s)
f.write(str(s))
f.close()
f.close()
f = open(TESTFN, 'r', s)
d = int(f.read())
f.close()
f.close()
except IOError, msg:
raise TestFailed, 'error setting buffer size %d: %s' % (s, str(msg))
if d != s:
raise TestFailed, 'readback failure using buffer size %d'
methods = ['fileno', 'flush', 'isatty', 'next', 'read', 'readinto',
'readline', 'readlines', 'seek', 'tell', 'truncate', 'write',
'xreadlines', '__iter__']
2002-06-11 03:22:31 -03:00
if sys.platform.startswith('atheos'):
methods.remove('truncate')
for methodname in methods:
method = getattr(f, methodname)
try:
method()
except ValueError:
pass
else:
raise TestFailed, 'file.%s() on a closed file should raise a ValueError' % methodname
try:
f.writelines([])
except ValueError:
pass
else:
raise TestFailed, 'file.writelines([]) on a closed file should raise a ValueError'
os.unlink(TESTFN)
def bug801631():
# SF bug <http://www.python.org/sf/801631>
# "file.truncate fault on windows"
f = file(TESTFN, 'wb')
f.write('12345678901') # 11 bytes
f.close()
f = file(TESTFN,'rb+')
data = f.read(5)
if data != '12345':
raise TestFailed("Read on file opened for update failed %r" % data)
if f.tell() != 5:
raise TestFailed("File pos after read wrong %d" % f.tell())
f.truncate()
if f.tell() != 5:
raise TestFailed("File pos after ftruncate wrong %d" % f.tell())
f.close()
size = os.path.getsize(TESTFN)
if size != 5:
raise TestFailed("File size after ftruncate wrong %d" % size)
try:
bug801631()
finally:
os.unlink(TESTFN)
# Test the complex interaction when mixing file-iteration and the various
# read* methods. Ostensibly, the mixture could just be tested to work
# when it should work according to the Python language, instead of fail
# when it should fail according to the current CPython implementation.
# People don't always program Python the way they should, though, and the
# implemenation might change in subtle ways, so we explicitly test for
# errors, too; the test will just have to be updated when the
# implementation changes.
dataoffset = 16384
filler = "ham\n"
assert not dataoffset % len(filler), \
"dataoffset must be multiple of len(filler)"
nchunks = dataoffset // len(filler)
testlines = [
"spam, spam and eggs\n",
"eggs, spam, ham and spam\n",
"saussages, spam, spam and eggs\n",
"spam, ham, spam and eggs\n",
"spam, spam, spam, spam, spam, ham, spam\n",
"wonderful spaaaaaam.\n"
]
methods = [("readline", ()), ("read", ()), ("readlines", ()),
("readinto", (array("c", " "*100),))]
try:
# Prepare the testfile
bag = open(TESTFN, "w")
bag.write(filler * nchunks)
bag.writelines(testlines)
bag.close()
# Test for appropriate errors mixing read* and iteration
for methodname, args in methods:
f = open(TESTFN)
if f.next() != filler:
raise TestFailed, "Broken testfile"
meth = getattr(f, methodname)
try:
meth(*args)
except ValueError:
pass
else:
raise TestFailed("%s%r after next() didn't raise ValueError" %
(methodname, args))
f.close()
# Test to see if harmless (by accident) mixing of read* and iteration
# still works. This depends on the size of the internal iteration
# buffer (currently 8192,) but we can test it in a flexible manner.
# Each line in the bag o' ham is 4 bytes ("h", "a", "m", "\n"), so
# 4096 lines of that should get us exactly on the buffer boundary for
# any power-of-2 buffersize between 4 and 16384 (inclusive).
f = open(TESTFN)
for i in range(nchunks):
f.next()
testline = testlines.pop(0)
try:
line = f.readline()
except ValueError:
raise TestFailed("readline() after next() with supposedly empty "
"iteration-buffer failed anyway")
if line != testline:
raise TestFailed("readline() after next() with empty buffer "
"failed. Got %r, expected %r" % (line, testline))
testline = testlines.pop(0)
buf = array("c", "\x00" * len(testline))
try:
f.readinto(buf)
except ValueError:
raise TestFailed("readinto() after next() with supposedly empty "
"iteration-buffer failed anyway")
line = buf.tostring()
if line != testline:
raise TestFailed("readinto() after next() with empty buffer "
"failed. Got %r, expected %r" % (line, testline))
testline = testlines.pop(0)
try:
line = f.read(len(testline))
except ValueError:
raise TestFailed("read() after next() with supposedly empty "
"iteration-buffer failed anyway")
if line != testline:
raise TestFailed("read() after next() with empty buffer "
"failed. Got %r, expected %r" % (line, testline))
try:
lines = f.readlines()
except ValueError:
raise TestFailed("readlines() after next() with supposedly empty "
"iteration-buffer failed anyway")
if lines != testlines:
raise TestFailed("readlines() after next() with empty buffer "
"failed. Got %r, expected %r" % (line, testline))
# Reading after iteration hit EOF shouldn't hurt either
f = open(TESTFN)
try:
for line in f:
pass
try:
f.readline()
f.readinto(buf)
f.read()
f.readlines()
except ValueError:
raise TestFailed("read* failed after next() consumed file")
finally:
f.close()
finally:
os.unlink(TESTFN)