import re

texts = [
	"The measurements are (w x h x l): 5x7x3cm", # => [(w,h,l)]
    "Measurement options are (wxhxl), (hxlxb): Some random stuff", # => [(w,h,l),(h,l,b)]
    "The measurements, in form wxhxl: 5x7x3cm" # => [(w,h,l)] 
]
for text in texts:
	print( [tuple(''.join(x.split()).split('x')) for x in re.findall(r'\b[whlb](?:\s*x\s*[whlb])+\b', text)] )