import re
str = "4,5cm x55x 22cm ";
regex = "(?P<l>[\d|,]+)(.*?)x(.*?)(?P<w>[\d|,]+)(.*?)x(.*?)(?P<h>[\d|,]+)(.*?)"
resultado = re.match(regex, str)
print resultado.groupdict()['l']
print resultado.groupdict()['w']
print resultado.groupdict()['h']
aW1wb3J0IHJlCnN0ciA9ICI0LDVjbSB4NTV4IDIyY20gIjsKcmVnZXggPSAiKD9QPGw+W1xkfCxdKykoLio/KXgoLio/KSg/UDx3PltcZHwsXSspKC4qPyl4KC4qPykoP1A8aD5bXGR8LF0rKSguKj8pIgpyZXN1bHRhZG8gPSByZS5tYXRjaChyZWdleCwgc3RyKQpwcmludCByZXN1bHRhZG8uZ3JvdXBkaWN0KClbJ2wnXQpwcmludCByZXN1bHRhZG8uZ3JvdXBkaWN0KClbJ3cnXQpwcmludCByZXN1bHRhZG8uZ3JvdXBkaWN0KClbJ2gnXQ==