Dear All,
I have a text based file look like this:
sample.txt
#int_val float_val str_val
1 1.23 sample1
2 2.12 sample2
3 3.1 sample3
Now I want to read it into a pytables table, using it's embedded numpy
array function process those columns, then store a data copy to a sqlite
database as well as a hdf5 table, better write to a new text file either.
I read the manual and found numpy.loadtxt can read the text, however, I
get no idea how to do it in pytables.
And one more question is for the column str_val, so far as I know, the
numpy array's dtype for string is come with limited length, if I need
change the string "sample3" to a "long_long_long_string", how I can
change the str_val's dtype and make sure the remained data (sample1 and
sample2 in this case) unchanged? I tested in numpy and found it not works.
>>>array(['sample1', 'sample2', 'sample3'],
dtype='|S7')
>>>arr.dtpye='|S14'
ValueError: new type not compatible with array.
Then I want to know if there's solution in pytables can solve this problem?
I am new to pytables, may I ask expert give a code sample for this case
here?
PS, can I read the sqlite database's data into a pytables table without
pain directly?
Thanks!
Rgs,
KC
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