import re
# val = "110" # => <_sre.SRE_Match object; span=(14, 17), match='110'>
val = "10"
s = "can there be B110 numbers and 10 numbers in this sentence"
print(re.search(r'(?<!__num)(?<!\d){}(?!\d)'.format(val), s))
# => <_sre.SRE_Match object; span=(30, 32), match='10'>