Raise the right exception (ValueError) for attempted I/O on closed StringIO
objects; this makes the emulation of file objects a bit better, and the
exceptions explain things a bit better.
diff --git a/Lib/StringIO.py b/Lib/StringIO.py
index dba38e4..fc195b9 100644
--- a/Lib/StringIO.py
+++ b/Lib/StringIO.py
@@ -41,8 +41,12 @@
self.closed = 1
del self.buf, self.pos
def isatty(self):
+ if self.closed:
+ raise ValueError, "I/O operation on closed file"
return 0
def seek(self, pos, mode = 0):
+ if self.closed:
+ raise ValueError, "I/O operation on closed file"
if self.buflist:
self.buf = self.buf + string.joinfields(self.buflist, '')
self.buflist = []
@@ -52,8 +56,12 @@
pos = pos + self.len
self.pos = max(0, pos)
def tell(self):
+ if self.closed:
+ raise ValueError, "I/O operation on closed file"
return self.pos
def read(self, n = -1):
+ if self.closed:
+ raise ValueError, "I/O operation on closed file"
if self.buflist:
self.buf = self.buf + string.joinfields(self.buflist, '')
self.buflist = []
@@ -65,6 +73,8 @@
self.pos = newpos
return r
def readline(self, length=None):
+ if self.closed:
+ raise ValueError, "I/O operation on closed file"
if self.buflist:
self.buf = self.buf + string.joinfields(self.buflist, '')
self.buflist = []
@@ -87,6 +97,8 @@
line = self.readline()
return lines
def write(self, s):
+ if self.closed:
+ raise ValueError, "I/O operation on closed file"
if not s: return
if self.pos > self.len:
self.buflist.append('\0'*(self.pos - self.len))
@@ -105,7 +117,8 @@
def writelines(self, list):
self.write(string.joinfields(list, ''))
def flush(self):
- pass
+ if self.closed:
+ raise ValueError, "I/O operation on closed file"
def getvalue(self):
if self.buflist:
self.buf = self.buf + string.joinfields(self.buflist, '')