Ok here is my version of doing this. I noticed that you want your output to be 7, which means you dont want to count special characters and numbers. So here is regex pattern:
re.findall("[a-zA-Z_]+", string)
Where [a-zA-Z_] means it will match any character beetwen a-z (lowercase) and A-Z (upper case).
About spaces. If you want to remove all extra spaces, just do:
string = string.rstrip().lstrip() # Remove all extra spaces at the start and at the end of the string
while " " in string: # While there are 2 spaces beetwen words in our string...
string = string.replace(" ", " ") # ... replace them by one space!