rst2ipynb-sageblock-filter

#!/usr/bin/env python

import json
import warnings

"""
Pandoc filter to convert all regular text to uppercase.
Code, link URLs, etc. are not affected.
"""

from pandocfilters import toJSONFilter, CodeBlock, Math


def python_input_format(text):
    return CodeBlock([u'', [u'python', u'input'], []], text)


def python_doctest_input_format(text):
    return python_input_format(text)


def sage_input_format(text):
    return python_input_format(text)


def output_format(text):
    return CodeBlock([u'', [u'json', u'output'], []],
                     json.dumps([{'data': {'text/plain': text},
                                  'execution_count': 1,
                                  'metadata': {},
                                  'output_type': 'execute_result'}]))


class Block:
    pass

math_characters = r'\^_'


def reformat_math(key, value, format, meta):
    if key != 'Str':
        return
    if not any(c in value for c in math_characters):
        return
    return Math([], value)


def reformat_sage_block(key, value, format, meta):
    if key != 'CodeBlock':
        return
    format, string = value
    if "\t" in string:
        warnings.warn("String contain <tab> character:\n"+string)
        exit(0)
    lines = string.split('\n')
    result = []
    current = Block()
    current.format = None
    current.value = ""

    def push():
        if current.format:
            result.append(current.format(current.value))
            current.format = None
            current.value = ""

    for line in lines:

        if line.startswith("sage: "):
            if current.format == sage_input_format:
                # Concatenate together contiguous sage inputs
                current.value += "\n"+line[6:]
            else:
                push()
                current.format = sage_input_format
                current.value = line[6:]
        elif line.startswith(">>> "):
            if current.format == python_doctest_input_format:
                # Concatenate together contiguous python
                current.value += "\n" + line[4:]
            else:
                push()
                current.format = python_doctest_input_format
                current.value = line[4:]
        elif line.startswith("....: "):
            if current.format != sage_input_format:
                msg = "continuation prompt not following a sage prompt: %s"
                warnings.warn(msg % line)
            current.value += "\n" + line[6:]
        # the final "..." may not have a trailing whitespace
        elif ((line.startswith("... ") or line == "...") and
              current.format != output_format):
            if current.format != python_doctest_input_format:
                msg = "continuation prompt not following a python prompt: %s"
                warnings.warn(msg % line)
            else:
                current.value += "\n" + line[4:]
        else:  # doesn't have leading prompts

            if current.format is None:  # first line of a code block

                current.format = python_input_format

            elif (current.format == sage_input_format or
                  current.format == python_doctest_input_format):
                # subsequent lines in block with prompts

                push()  # reset format
                if line:
                    current.format = output_format
                else:
                    continue

            if current.value:
                current.value += "\n" + line
            else:
                current.value = line

    push()
    return result

if __name__ == "__main__":
  toJSONFilter(reformat_sage_block)
#  toJSONFilter(reformat_math)