markdown math engine | Python Fiddle

import re

def t_SUB(scanner, token): return "SUB", "<sub>"+token[1:]+"</sub>"
def t_MD(scanner, token):   return "MD", token
def t_EVAL(scanner, token): return "EVAL", token[:-1]+str(eval(token[:-2]))
def t_MATH(scanner, token): return "MATH", token[1:]

def scan1(text):
    scanner1 = re.Scanner([
        (r">[^\n]+", t_MATH),
        (r"[^>]+", t_MD),
        (r"\^[^ ]+", t_SUB),
        (r"\s+", None),
        ])
    parse1 = ""
    tokens, remainder = scanner1.scan(text)
    for token in tokens:
         if token[0]=="MATH":
            parse1+=scan2(token[1])+""
         else:
            parse1+=token[1]+""
    return parse1

def scan2(text):
    scanner2 = re.Scanner([
        (r"\^[^ ]+", t_SUB),
        #(r'[^=]+==',t_EVAL)
        ])
    parse2 = ""
    tokens, remainder = scanner2.scan(text)
    for token in tokens:
         parse2 +=">"+token[1]+" "
    return parse2

md="""Math in markdown
================

>3**7==

Then we multiply by 4 because there is 4 legs,
>3*4=="""
print scan1(md)

Browser Version Not Supported

Due to Python Fiddle's reliance on advanced JavaScript techniques, older browsers might have problems running it correctly. Please download the latest version of your favourite browser.
Chrome 10+ Firefox 4+ Safari 5+
IE 10+

Let me try anyway!

Python Fiddle

Python Cloud IDE