[Numpy-discussion] loadtxt stop

[Christopher Barker]

Neil Hodgson wrote:
> In the end, the question was; is worth adding start= and stop= markers 
> into loadtxt to allow grabbing sections of a file between two known 
> headers?  I imagine it's something that people come up against regularly.

maybe not so regular. However, a common use would be to be able load 
only n rows, which also does not appear to be supported. That would be nice.

-Chris



> Thanks,
> Neil 
> 
> ------------------------------------------------------------------------
> *From:* Neil Hodgson <hodgson.neil at yahoo.co.uk>
> *To:* numpy-discussion at scipy.org
> *Sent:* Fri, 17 September, 2010 14:17:12
> *Subject:* loadtxt stop
> 
> Hi,
> 
> I been looking around and could spot anything on this.  Quite often I 
> want to read a homogeneous block of data from within a file.  The 
> skiprows option is great for missing out the section before the data 
> starts, but if there is anything below then loadtxt will choke.  I 
> wondered if there was a possibility to put an endmarker= ?
> 
> For example, if I want to load text from a large! file that looks like this
> 
> header line
> header line
> 1 2.0 3.0
> 2 4.5 5.7
> ...
> 500 4.3 5.4
> END
> more headers
> more headers
> 1 2.0 3.0 3.14 1.1414
> 2 4.5 5.7 1.14 3.1459
> ...
> 500 4.3 5.4 0.000 0.001
> END
> 
> Then I can use skiprows=2, but loadtxt will choke when it gets to 
> 'END'.  To read t
> 
> 
> 
> ------------------------------------------------------------------------
> 
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