Upabjojr/fullform2sympy.py

## fullform2sympy.py
import re

replacements = dict(
    Times="Mul",
    Plus="Add",
    Power="Pow",
)

def parse_full_form(wmexpr):
    out = []
    stack = [out]
    generator = re.finditer(r'[\[\],]', wmexpr)
    last_pos = 0
    for match in generator:
        if match is None:
            break
        position = match.start()
        last_expr = wmexpr[last_pos:position].replace(',', '').replace(']', '').replace('[', '').strip()

        if match.group() == ',':
            if last_expr != '':
                stack[-1].append(last_expr)
        elif match.group() == ']':
            if last_expr != '':
                stack[-1].append(last_expr)
            stack.pop()
            current_pos = stack[-1]
        elif match.group() == '[':
            stack[-1].append([last_expr])
            stack.append(stack[-1][-1])
        last_pos = match.end()
    return out[0]


def generate_sympy_from_parsed(parsed, depth=0):
    out = ""
    if not isinstance(parsed, list):
        return parsed
    if parsed[0] == "If":
        out += "\nif ("+generate_sympy_from_parsed(parsed[1])+"):\n"
        out += shift4(generate_sympy_from_parsed(parsed[2]))
        if len(parsed) > 2:
            out += "\nelse:\n"
            out += shift4(generate_sympy_from_parsed(parsed[3]))
    else:
        if parsed[0] in replacements:
            out += replacements[parsed[0]]
        else:
            out += parsed[0]
        if len(parsed) == 1:
            return out
        out += "("
        out += ", ".join([generate_sympy_from_parsed(i) for i in parsed[1:]])
        out += ")"
    return out

def shift4(out):
    return ' '*4 + re.sub(r'\n', '\n    ', out)

## gistfile1.txt
A Mathematica expression should be exposed to both __HoldForm__ and __FullForm__, that is

FullForm[HoldForm[ expression ]]

after this, copy the result into a Python string, let's say _expr_, then call:

list_tree = parse_full_form(expr)
generate_sympy_from_parsed(list_tree)
	import re

	replacements = dict(
	Times="Mul",
	Plus="Add",
	Power="Pow",
	)

	def parse_full_form(wmexpr):
	out = []
	stack = [out]
	generator = re.finditer(r'[\[\],]', wmexpr)
	last_pos = 0
	for match in generator:
	if match is None:
	break
	position = match.start()
	last_expr = wmexpr[last_pos:position].replace(',', '').replace(']', '').replace('[', '').strip()

	if match.group() == ',':
	if last_expr != '':
	stack[-1].append(last_expr)
	elif match.group() == ']':
	if last_expr != '':
	stack[-1].append(last_expr)
	stack.pop()
	current_pos = stack[-1]
	elif match.group() == '[':
	stack[-1].append([last_expr])
	stack.append(stack[-1][-1])
	last_pos = match.end()
	return out[0]


	def generate_sympy_from_parsed(parsed, depth=0):
	out = ""
	if not isinstance(parsed, list):
	return parsed
	if parsed[0] == "If":
	out += "\nif ("+generate_sympy_from_parsed(parsed[1])+"):\n"
	out += shift4(generate_sympy_from_parsed(parsed[2]))
	if len(parsed) > 2:
	out += "\nelse:\n"
	out += shift4(generate_sympy_from_parsed(parsed[3]))
	else:
	if parsed[0] in replacements:
	out += replacements[parsed[0]]
	else:
	out += parsed[0]
	if len(parsed) == 1:
	return out
	out += "("
	out += ", ".join([generate_sympy_from_parsed(i) for i in parsed[1:]])
	out += ")"
	return out

	def shift4(out):
	return ' '*4 + re.sub(r'\n', '\n ', out)
	A Mathematica expression should be exposed to both __HoldForm__ and __FullForm__, that is

	FullForm[HoldForm[ expression ]]

	after this, copy the result into a Python string, let's say _expr_, then call:

	list_tree = parse_full_form(expr)
	generate_sympy_from_parsed(list_tree)