my_list = [("31", "py"), ("22", "226.65"), ("18.12", "17"), ("pyt", "12")]

print("列表为:")
print(my_list)

my_result = []
for index in my_list:
   my_temp = []
   for element in index:

      if element.isalpha():
         my_temp.append(element)
      else:

         my_temp.append(float(element))
   my_result.append((my_temp[0],my_temp[1]))

print("结果为:")
print(my_result)

列表为:
[('31', 'py'), ('22', '226.65'), ('18.12', '17'), ('pyt', '12')]
结果为:
[(31.0, 'py'), (22.0, 226.65), (18.12, 17.0), ('pyt', 12.0)]