如果 dict 值的位数超过指定的位数，则引发错误

Question

I'm trying to raise an error if a value in a dict has greater than eg 6 digits (would be useful to test for a particular number of decimal places too).

eg for the dict below (and say number digits = 6)

example_dict = {'dict_id': 12345,
                 'key1': 10501.04999999999999999262}
for key, value in tariff_detail.items():
    if value == type(float) and (test for number of digits):
        raise ValueError("DictID: {}, Key Missing: {}".format(example_dict['dict_id'],key))

(Note if I stick the above example in ipython and do example_dict.values() it pops out [10501.05] - Is there in built rounding or is this just for display?)

What's the best way to test for the number of digits and raise an error on fail?

Answer 1

一种简单的方法是将值转换为字符串，然后计算其长度：

if len(str(value)) > 6 :