Question

How can I automatically process ascending file names and array names in Numpy:

I have a series of HDF5 files named:

20120101.hdf5, 20120102.hdf5, 20120103.hdf5, ..., 20120130.hdf5, 20120131.hdf5  

each of the hdf5 file contains several arrays naming:

array1, array2, array3, ..., array24

I want to modify each of the arrays seperately and then create corresponding new hdf5 files. For example, using 20120101.hdf5:

import numpy
import tables

file = openFile("20120101.hdf5","r")
b1 = file.root.array1
c1 = (b1<=1)
new20120101_array1 = creatArray('/','1',c1)
c2 = ((b1<=2) and (b>1))
new20120101_array1 = creatArray('/','2',c2)
.
.
.

c20 = ((b1<=20) and (b>19))
new20120101_array1 = creatArray('/','20',c20)

and repeat it for arrays 2-24. As a result, I want to have:

new20120101.hdf5 ---- new20120101_array1 ---- 1
                                              2
                                              ...
                                              20
                 ---- new20120101_array2 ---- 1
                                              ...
                                              20
                 ...
                 ---- new20120101_array24 --- 1
                                              ...
                                              20
new20120102.hdf5
....
new20120131.hdf5

Answer 1

If you have several files in a directory, you can use the os.listdir function, which returns a list containing the names of the entries in the directory.

Example:

import os
import tables

direc = '/Users/cg/' # the working directory (where your files are stored)
dirs = os.listdir(direc)

for idir in dirs: # this will iterate over the files in your working directory

    if idir.endswith('.he5'): # only for HDF5 files...
        hdf5 = tables.openFile(os.path.join(direc,idir))

        #### DO WHAT YOU WANT WITH EACH FILE!

        hdf5.close()

The other part of your question is already answered in your other question, I guess (you can use the walkNodes function ).