python - 如何解决 TypeError 的问题：传递给 numpy.ndarray.__format__ 的格式字符串不受支持

Question

我有以下代码，但输出给我一个错误。

possible_rolls = arr = np.array([1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20])
roll_result = np.random.choice(possible_rolls,1,replace=True)
modified_result = roll_result + 11
action_succeeded = modified_result > 15

print("On a modified roll of {:d}, Alice's action {}.".format(modified_result, "succeeded" if action_succeeded else "failed"))

TypeError：传递给 numpy.ndarray 的格式字符串不受支持。格式

标签： pythonpandasnumpy

Answer 1

那是因为modified_result是一个数组，而不是一个数字：

possible_rolls = arr = np.array([1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20])
roll_result = np.random.choice(possible_rolls,1,replace=True)
modified_result = roll_result + 11
action_succeeded = modified_result > 15

print(type(modified_result))
>>> <class 'numpy.ndarray'>

这将解决问题：

print("On a modified roll of {:d}, Alice's action {}.".format(modified_result[0], "succeeded" if action_succeeded else "failed"))

>>> On a modified roll of 13, Alice's action failed.