Re: [PATCH] ob-python results handling for dicts, dataframes, arrays, and plots

[Liu Hui]

Hi,

Thank you for the patch!

> Next, for numpy arrays and pandas dataframes/series: these are
> converted to tables, for example:
>
> #+begin_src python
>   import pandas as pd
>   import numpy as np
>
>   return pd.DataFrame(np.array([[1,2,3],[4,5,6]]),
>                       columns=['a','b','c'])
> #+end_src
>
> #+RESULTS:
> |   | a | b | c |
> |---+---+---+---|
> | 0 | 1 | 2 | 3 |
> | 1 | 4 | 5 | 6 |
>
> To avoid conversion, you can specify "raw", "verbatim", "scalar", or
> "output" in the ":results" header argument.

Do we need to limit the table/list size by default, or handle them
only with relevant result type (e.g. `table/list')? Dataframe/array
are often large. The following results are truncated by default
previously, which can be tweaked via np.set_printoptions and
pd.set_option.

#+begin_src python
import numpy as np
return np.random.randint(10, size=(30,40))
#+end_src

#+begin_src python
import numpy as np
return np.random.rand(20,3,4,5)
#+end_src

#+begin_src python
import pandas as pd
import numpy as np

d = {'col1': np.random.rand(100), 'col2': np.random.rand(100)}
return pd.DataFrame(d)
#+end_src

> +def __org_babel_python_format_value(result, result_file, result_params):
> +    with open(result_file, 'w') as f:
> +        if 'graphics' in result_params:
> +            result.savefig(result_file)
> +        elif 'pp' in result_params:
> +            import pprint
> +            f.write(pprint.pformat(result))
> +        else:
> +            if not set(result_params).intersection(\
> +['scalar', 'verbatim', 'raw']):
> +                try:
> +                    import pandas
> +                except ImportError:
> +                    pass
> +                else:
> +                    if isinstance(result, pandas.DataFrame):
> +                        result = [[''] + list(result.columns), None] + \

Here we can use '{}'.format(df.index.name) to show the name of index

>  (defun org-babel-python-format-session-value
>      (src-file result-file result-params)
>    "Return Python code to evaluate SRC-FILE and write result to RESULT-FILE."
> -  (format "\
> +  (concat org-babel-python--def-format-value
> +      (format "

Maybe `org-babel-python--def-format-value' can be evaluated only once
in the session mode? It would shorten the string sent to the python
shell, where temp files are used for long strings.