[New-bugs-announce] [issue5513] "What's New" should say VERY CLEARLY that the type file is gone

Mitchell Model report at bugs.python.org
Wed Mar 18 23:26:17 CET 2009


New submission from Mitchell Model <mlm at acm.org>:

MAIN POINT

The Python 3 "What's New" should SCREAM that the type file is gone, not 
just that people should use the function open() to open files, since 
that has been a recommendation for quite a while.

EXPLANATION

In multiple readings of the Python 3 "What's New" I blew right past the 
"Removed file. Use open().", since I've been using open() instead of 
file() for a long time. I didn't notice that unlike the preceding 
several lines, there were no parentheses after "file" and that this line 
was literally saying there was no longer a type called "file".

OBSERVATIONS

(1) If the line is meant to say that you can no longer call file() as a 
function -- which would be strange if it were still a type -- then it is 
missing its parentheses.

(2) If the line is meant to say that there is no longer a file type, as 
it apparently means to say since in fact -- and to my great surprise -- 
there really IS no type called "file" in Python 3 (I discovered that 
doing a dir(file) to check whether file provided method function I 
thought it did instead of taking the time to look it up.) then there is 
a grammatical problem with the line since a (n old) type shouldn't be 
equated to a function call.

(3) I predict that anyone who has more than a passing acquaintance with 
Python 2 will be similarly shocked when they find out that what they get 
back from open() is a _io.TextIOWrapper (and, by the way, that they have 
to import _io or at least _io.TextIOWrapper to be able to do a dir on 
it). Likewise for help(file) and help(_io.TextIOWrapper). There should 
be a very prominent statement that as part of the reimplementation of 
the io system, the type file has been replaced by _io.TextIOWrapper.

RECOMMENDATION

The line
    "Removed file. Use open()."
should be replaced with:
    "The type file has been removed; use open() to open a file."
or possibly:
    "The type file has been replaced by _ioTextIOWrapper; use open() to 
open a file; open returns an instance of _ioTextIOWrapper."

----------
assignee: georg.brandl
components: Documentation
messages: 83783
nosy: MLModel, georg.brandl
severity: normal
status: open
title: "What's New" should say VERY CLEARLY that the type file is gone
versions: Python 3.0, Python 3.1

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Python tracker <report at bugs.python.org>
<http://bugs.python.org/issue5513>
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