You cannot do what you want with just .replace(). From the BeautifulSoup documentation on NavigableString:
You can’t edit a string in place, but you can replace one string with another, using replace_with().
That's exactly what you need to do; take each match, then call .replace() on the contained text and replace the original with that:
findtoure = commentary.find_all(text = re.compile('Gnegneri Toure Yaya'))
for comment in findtoure:
fixed_text = comment.replace('Gnegneri Toure Yaya', 'Yaya Toure')
comment.replace_with(fixed_text)
If you want to use these comments further, you'll need to do a new find:
findtoure = commentary.find_all(text = re.compile('Yaya Toure'))
or, if you all you need is the resulting strings (so Python str objects, not NavigableString objects still connected to the BeautifulSoup object), just collect the fixed_text objects:
findtoure = commentary.find_all(text = re.compile('Gnegneri Toure Yaya'))
fixed_comments = []
for comment in findtoure:
fixed_text = comment.replace('Gnegneri Toure Yaya', 'Yaya Toure')
comment.replace_with(fixed_text)
fixed_comments.append(fixed_text)
