cStringIO.StringIO has no write method?

[Peter Otten]

Laszlo Nagy wrote:

> This program:
> 
> import sys
> import traceback
> import cStringIO
> 
> a = 1.0
> b = 0.0
> try:
>     c=a/b
> except:
>     f = cStringIO.StringIO('')
>     ei = sys.exc_info()
>     traceback.print_exception(ei[0],ei[1],ei[2],file=f)
> 
> raises this exception:
> 
> Traceback (most recent call last):
>   File "C:/Documents and Settings/gandalf/test.py", line 12, in ?
>     traceback.print_exception(ei[0],ei[1],ei[2],file=f)
>   File "C:\Python24\Lib\traceback.py", line 124, in print_exception
>     _print(file, 'Traceback (most recent call last):')
>   File "C:\Python24\Lib\traceback.py", line 13, in _print
>     file.write(str+terminator)
> AttributeError: 'cStringIO.StringI' object has no attribute 'write'
> 
> What is 'cStringIO.StringI' anyway? Shouldn't it be 'cStringIO.StringIO'?

See http://docs.python.org/lib/module-cStringIO.html:

"""
Another difference from the StringIO module is that calling StringIO() with
a string parameter creates a read-only object. Unlike an object created
without a string parameter, it does not have write methods. These objects
are not generally visible. They turn up in tracebacks as StringI and
StringO. 
"""

Peter