[Python-checkins] CVS: python/dist/src/Lib/test test_descr.py,1.50,1.51

[Tim Peters]

Update of /cvsroot/python/python/dist/src/Lib/test
In directory usw-pr-cvs1:/tmp/cvs-serv20497/python/Lib/test

Modified Files:
	test_descr.py 
Log Message:
SF bug [#460467] file objects should be subclassable.
Preliminary support.  What's here works, but needs fine-tuning.


Index: test_descr.py
===================================================================
RCS file: /cvsroot/python/python/dist/src/Lib/test/test_descr.py,v
retrieving revision 1.50
retrieving revision 1.51
diff -C2 -d -r1.50 -r1.51
*** test_descr.py	2001/09/12 19:53:15	1.50
--- test_descr.py	2001/09/13 05:38:55	1.51
***************
*** 1,5 ****
  # Test descriptor-related enhancements
  
! from test_support import verify, verbose, TestFailed
  from copy import deepcopy
  
--- 1,5 ----
  # Test descriptor-related enhancements
  
! from test_support import verify, verbose, TestFailed, TESTFN
  from copy import deepcopy
  
***************
*** 1636,1639 ****
--- 1636,1686 ----
      verify(u[0:0].__class__ is unicode)
      verify(u[0:0] == u"")
+ 
+     class CountedInput(file):
+         """Counts lines read by self.readline().
+ 
+         self.lineno is the 0-based ordinal of the last line read, up to
+         a maximum of one greater than the number of lines in the file.
+ 
+         self.ateof is true if and only if the final "" line has been read,
+         at which point self.lineno stops incrementing, and further calls
+         to readline() continue to return "".
+         """
+ 
+         lineno = 0
+         ateof = 0
+         def readline(self):
+             if self.ateof:
+                 return ""
+             s = file.readline(self)
+             # Next line works too.
+             # s = super(CountedInput, self).readline()
+             self.lineno += 1
+             if s == "":
+                 self.ateof = 1
+             return s
+ 
+     f = open(TESTFN, 'w')
+     lines = ['a\n', 'b\n', 'c\n']
+     try:
+         f.writelines(lines)
+         f.close()
+         f = CountedInput(TESTFN)
+         for (i, expected) in zip(range(1, 5) + [4], lines + 2 * [""]):
+             got = f.readline()
+             verify(expected == got)
+             verify(f.lineno == i)
+             verify(f.ateof == (i > len(lines)))
+         f.close()
+     finally:
+         try:
+             f.close()
+         except:
+             pass
+         try:
+             import os
+             os.unlink(TESTFN)
+         except:
+             pass
  
  def all():