[ python-Feature Requests-1152248 ] Enhance file.readlines by making line separator selectable

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Feature Requests item #1152248, was opened at 2005-02-26 01:24
Message generated for change (Comment added) made by montanaro
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Category: Python Interpreter Core
Group: None
Status: Open
Resolution: None
Priority: 5
Submitted By: Nick Coghlan (ncoghlan)
Assigned to: Nobody/Anonymous (nobody)
Summary: Enhance file.readlines by making line separator selectable

Initial Comment:
There is no canonical way to iterate through a file on
chunks *other* than whole lines without reading the
whole file into memory.

Allowing the separator to be specified as an argument
to file.readlines and file.xreadlines would greatly
simplify the task.

See here for an example interface of the useful options:
http://mail.python.org/pipermail/python-list/2005-February/268482.html

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>Comment By: Skip Montanaro (montanaro)
Date: 2005-06-27 06:22

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Seems the most likely place you'd want to use this is to select a non-
native line ending in a situation where you didn't want to use universal
newlines (select \r as a line ending on Unix, for example, and allow
\n to just be another character).  In that case they'd clearly still be
lines, so embellishing the normal line reading machinery without
adding a new method would be most appropriate.


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Comment By: Nick Coghlan (ncoghlan)
Date: 2005-06-27 04:29

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As Douglas Alan's sample implementation (and his second
attempt [1]) show, getting this right (and reasonably
efficient) is actually a non-trivial exercise. Leveraging
the existing readlines infrastructure is an idea worth
considering.

[1]
http://mail.python.org/pipermail/python-list/2005-February/268547.html

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Comment By: Raymond Hettinger (rhettinger)
Date: 2005-06-26 23:25

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The OPs request is not a non-starter.  There is a proven 
precedent in AWK which allows programmer specifiable record 
separators.

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Comment By: Douglas Alan (nessus42)
Date: 2005-02-28 12:57

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In reply to birkenfeld, I'm not sure why you don't want to
call lines separated with an alternate line-separation
string "lines", but if you want to call them something else,
I should think they should be called "records" rather than
"chunks".

|>oug


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Comment By: Reinhold Birkenfeld (birkenfeld)
Date: 2005-02-26 01:38

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I don't know whether (x)readlines is the right place, since
you are _not_ operating on lines.

What about (x)readchunks?

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