def sort_tuples(tpl):
return sorted(tpl, key = lambda i: float(i[1]), reverse = False)
lst_tpl = [('aa', '7.23'), ('bb', '5.92'), ('cc', '1.29'), ('dd', '3.14')]
lst_tpl = sort_tuples(lst_tpl)
print(lst_tpl)
'''
run:
[('cc', '1.29'), ('dd', '3.14'), ('bb', '5.92'), ('aa', '7.23')]
'''