expression_expanssion.py

from pyparsing import *
import string 
from sympy import symbols

def getvars(opslist, varlist,vars):
    for i in opslist:
    	if isinstance(i, basestring) and i in ("&", "|"):
            continue
        if isinstance(i, list):
            getvars(i, varlist,vars)
        else:
            v = vars[len(varlist.keys())]
            varlist[i] =v
            vars.remove(v)
    return 0

def foo(inp):
    inp = inp.replace("*", "&").replace("+", "|")
    enclosed = Forward()
    nestedParens = nestedExpr('(', ')', content=enclosed)
    up = ''.join(set(filter(lambda x: x not in '()|" &', inp))).decode('latin-1').encode('utf-8')
    enclosed << (Word(up) | '&' | '|' | nestedParens | Suppress("2016"))
    # enclosed << ( Word(alphanums) | Word(alphas + up) | Word(nums) | '&' | '|' | nestedParens)
    vars = []
    for g in range(1, 6):
        vars += list("{}0{}".format(i, g) for i in string.ascii_uppercase)
    ninp = "(" + inp + ")"
    opslist = enclosed.parseString(ninp).asList()
    varlist = {}
    getvars(opslist, varlist, vars)
    varlist = {i[0]: i[1] for i in varlist.items()}
    for v in sorted(varlist, key=len, reverse=True):  # Through keys sorted by length
        ninp = ninp.replace(v, varlist[v])

    x = '{}=symbols("{}")'.format(",".join(varlist[v] for v in varlist), " ".join(varlist[v] for v in varlist))
    exec x in globals(), locals()
    exp = str(eval(ninp.replace("&", "*").replace("|", "+")).expand())
    
    for v in varlist:
        exp = exp.replace(varlist[v], v)
    return "{}".format(" + ".join(["({})".format(i.strip()) if "*" in i else "{}".format(i.strip())  for i in exp.split("+")])).strip().replace("*", " * ")
    



my_str = ['("word 1" + "word 2") * "word 3"',
          '("word 1" + "word 2") * ("word 3" + "word 4")',
          '(("word 1" + "word 2") * ("word 3" + "word 4")) * "word 5"',
         ]
a = []
for i in my_str:  
    a.append(foo(i))

print a