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)] )
aW1wb3J0IHJlCgp0ZXh0cyA9IFsKCSJUaGUgbWVhc3VyZW1lbnRzIGFyZSAodyB4IGggeCBsKTogNXg3eDNjbSIsICMgPT4gWyh3LGgsbCldCiAgICAiTWVhc3VyZW1lbnQgb3B0aW9ucyBhcmUgKHd4aHhsKSwgKGh4bHhiKTogU29tZSByYW5kb20gc3R1ZmYiLCAjID0+IFsodyxoLGwpLChoLGwsYildCiAgICAiVGhlIG1lYXN1cmVtZW50cywgaW4gZm9ybSB3eGh4bDogNXg3eDNjbSIgIyA9PiBbKHcsaCxsKV0gCl0KZm9yIHRleHQgaW4gdGV4dHM6CglwcmludCggW3R1cGxlKCcnLmpvaW4oeC5zcGxpdCgpKS5zcGxpdCgneCcpKSBmb3IgeCBpbiByZS5maW5kYWxsKHInXGJbd2hsYl0oPzpccyp4XHMqW3dobGJdKStcYicsIHRleHQpXSAp
[('w', 'h', 'l')]
[('w', 'h', 'l'), ('h', 'l', 'b')]
[('w', 'h', 'l')]