Re: maximum value in a column of file

thank you for your answer
actually i've to do some statistics (maximum,minimum,mean,standard
deviation,....) of a file of data in which each column is a particular
type of data. (the file is a tab separated value).
I was trying to do this by using python (usually i work with fortran or
bash, but i'm learning python), that the reason why i tried to use numpy.

numpy.loadtxt is probably what your looking for, provided your file
contains only numbers and comment lines.
check the example here: http://www.scipy.org/Numpy_Example_List_With_Doc#head-88ade192dacf0c15e4f1377096134ee559df07a0

X = numpy.loadtxt('data.txt')
X[:,0].mean() # mean of first column
X[:,0].max() # mux of first column
X[:,0].var() # variance of first column
....

enjoy! bernhard



As I implied, you can do all this in standard Python "by hand", but
numpy/scipy can definitely make things easier. There's a dependency
cost here (your program needs one or more extra libraries to work), but
if that's no problem in your environment, I'd recommend that approach.

The scipy add-on contains a bunch of things for file i/o; see

http://www.scipy.org/doc/api_docs/SciPy.io.html

for an overview. Since you're reading text files, the "array_import"
module seems to be what you need:

http://www.scipy.org/doc/api_docs/SciPy.io.array_import.html

There are active user communities for both numpy and scipy that can help
you sort out any remaining issues; for details, see:

http://www.scipy.org/Mailing_Lists

Hope this helps!

</F>

.

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