Vocal Counting

You are required to deliver the following function in voc_module (file voc_module.py):

voc_count(s, sref)

such that

given

  • s a non-empty str.

  • sref a str of lowercase letters.

returns an int with the number of lowercase vocal letters occurring in s that do not occur in sref.

For example:


>>> sref = 'abcdefgh'
>>> voc_count('The 101 is txatxi piruli. The 100 is not.', sref)
7
>>> voc_count('1a2e3i4o5u6', sref)
3
>>> voc_count('_a:e-i/o#u-a.e;i=o4u', sref)
6
>>> voc_count('_a:e-a/a#e-a.e;a', sref)
0

Doctests are available in the voc_count.test file.