[Python-Dev] Mailbox module - timings and functionality changes (original) (raw)

Antoine Pitrou solipsis at pitrou.net
Wed Jun 30 18:42:58 CEST 2010

On Tue, 29 Jun 2010 20:05:29 -0400 "R. David Murray" <rdmurray at bitdance.com> wrote:

I would imagine Guido is talking about an io.TextIOWrapper...in other words, take the binary file you've just finished grabbing info from, and reread it as a text file in order to grab the actual message content.

This sounds a bit suboptimal to me (and introduces race conditions if e.g. the file is replaced with another one before you reopen it). You could instead decode the binary data by yourself, especially if you have already stored that data somewhere.

Also, please note that values used by seek() and tell() on text I/O are "opaque cookies". While they can happen to match the raw binary file position, it is a mere coincidence (or an implementation detail, at your will). Therefore, reusing tell() values of a binary file to seek() a TextIOWrapper accessing the same file is wrong.

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