Databases
StackOverflow2013
Postsdbo
POWhat's the pythonic way to reconstruct a serialized object
 

Note that there are some explanatory texts on larger screens.

plurals
  1. POWhat's the pythonic way to reconstruct a serialized object
    primarykey
    data
    text
    <p>the more I work with python, the more I want to do it the pythonic way, i.e. try to avoid isinstance queries etc. I am developing a framework for scientific parameter exploration for numeric simulation. </p> <p>I work with two hard constraints: First, I need to be able to repeat a specific simulation I stored to disk exactly the way it was run for the first time. Secondly, data should be nice and readable in hdf5/pytables format.</p> <p>Both concepts are a bit opposing. As soon as I store stuff as pytables data, some information is lost. For instance, after reloading a python int becomes a numpy.int64. This can be problematic if you want to rerun numerical simulations, because there are cases where a multiplication of a variable with an int works fine but breaks when used with numpy.int64. This is the case, for example, if you use the spiking neural network simulator BRIAN.</p> <p>So a straightforward answer would be to simply pickle everything and get it back as it was before. Yet, this doesn't work well with the idea of readable hdf5 array or table data. </p> <p>So what I have in mind is to store the original data format as an hdf5 attribute to the corresponding table or array and use this information to reconstruct the original data. First, is that a good idea in general, and second, what is the most pythonic way to do that?</p> <p>For instance, what about this:</p> <pre><code>original_class_name = data.__class__.__name__ # do the storage of data and the original_class_name {...} # load the hdf5data and reconstruct it reconstructed_data = eval(original_class_name+'(hdf5data)') </code></pre> <p>To me this seems too hacky.</p>
    singulars
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. PTQuestion
    1. This table or related slice is empty.
    1. USSmCaterpillar
    plurals
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. COWhy not serialize the objects with `pickle`, and have an extra file in hdf5 format for those who nead the human readable version?
      singulars
      1. POWhat's the pythonic way to reconstruct a serialized object
      1. USMichael Foukarakis
    2. COThis would be too much overhead. I am talking here about data from giga to terabytes. This makes me wonder anyway, whether the whole issue of reconstruction and type-checking is useful when it comes to very large data. I handle everything right now by being extremely restrictive, i.e. by type checking of data and refusing it directly in the beginning if it does not belong to a set of very native data (numpy and python native stuff).
      singulars
      1. POWhat's the pythonic way to reconstruct a serialized object
      1. USSmCaterpillar
    3. COAt any rate, proper serialization should take precedence, I think. If you want human-readable output, you can easily produce it from a serialized set of objects (just read them in and pretty-print them).
      singulars
      1. POWhat's the pythonic way to reconstruct a serialized object
      1. USMichael Foukarakis
 

Querying!

 
Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload