text = 'слово1 слово2 слово3 слово4 слово5 слово6 слово7 слово8 слово9 слово10'
def func(text, x):
new_list = []
text_list = text.split()
word = ''
n = 0
while len(text_list):
word += text_list.pop(0) + ' '
n += 1
if n >= x:
new_list.append(word.rstrip())
word = ''
n = 0
if word != '':
new_list.append(word.rstrip())
return new_list
print(func(text, 3))