from pyparsing import *
from string import *

def action(s, loc, toks):
    print('s', type(s), s)
    print('loc', type(loc), loc)
    print('toks', type(toks), toks)
    return ['<'] + list(toks) + ['>']


pattern = Suppress('[') + Word(digits) + '-' + Word(digits).setParseAction(action) + Suppress(']')

pattern.parseString('[0-9]')

# >>> pattern.parseString('test[0-9]test')
# ParseException: Expected "[" (at char 0), (line:1, col:1)

pattern.searchString('test[0-9]test')

pattern.searchString('test[0-9]test[0-9]')

list(pattern.scanString('test[0-9]test'))

list(pattern.scanString('test[0-9]test[0-9]'))

pattern.transformString('test[0-9]test[0-9]')

text = SkipTo(StringEnd() | '[')
numeric = Suppress('[') + Word(digits) + Suppress('-') + Word(digits) + Suppress(']')
pattern = ZeroOrMore(text | numeric)

def skip_empty(toks):
    if not toks[0]:
        raise ParseException('must be not empty')
        

text.addParseAction(skip_empty)

pattern.parseString('test[0-9]test[0-9]')

pattern.parseString('te\[\]st\\\\[0-9]test[0-9]')

escape = (Literal('\\\\').addParseAction(replaceWith('\\')) | 
          Literal('\\[').addParseAction(replaceWith('[')) |
          Literal('\\]').addParseAction(replaceWith(']')))
text = SkipTo(StringEnd() | '[', ignore=escape).setParseAction(skip_empty)
pattern = ZeroOrMore(text | numeric)

pattern.parseString('te\[\]st\\\\[0-9]test[0-9]')

def unescape(toks):
    return [escape.transformString(item) for item in toks]


text.addParseAction(unescape)

pattern.parseString('te\[\]st\\\\[0-9]test[0-9]')

def text_block(toks):
    return [iter(toks)]
    
    
def numeric_block(toks):
    from_value, to_value = toks
    return [map(str, range(int(from_value), int(to_value) + 1))]


text.addParseAction(text_block)
numeric.addParseAction(numeric_block)

pattern.parseString('te\[\]st\\\\[0-9]test[0-9]')

from itertools import product


def iterator(string):
    return (''.join(items) for items in product(*pattern.parseString(string)))

len(list(iterator('te\[\]st\\\\[0-9]test[0-9]')))

list(iterator('te\[\]st\\\\[0-9]test[0-9]'))[:3]

list(iterator('te\[\]st\\\\[0-9]test[0-9]'))[-3:]