Python类型错误:元组索引必须是整数或切片，而不是元组

Question

试图让一大块代码工作，而我的一个测试用例失败了。它应该返回：

Invalid Point! (7, 8, 9, 10)
Invalid Point! ('hi', 2, 3)
((1, 2, 3), (4, 5, 6))

相反，我得到了标题中提到的TypeError和Invalid Point! (1, 2, 3)

以下代码供参考。

def collection_check(a_coll, coll_template):
#Receives a collection to check and a template collection to check against.  The procedure
#raises errors if the collection to check is the incorrect type, is the wrong length, or 
#contains data types that do not match the data types of the provided template.
if not type(a_coll)==type(coll_template):
out_str = "TypeError:{} and template are different classes."
raise TypeError(out_str.format(a_coll))
if not(len(a_coll)==len(coll_template)):
out_str = "ValueError:{} and template are different lengths." 
raise ValueError(out_str.format(a_coll))
for i in range(len(a_coll)):
if not(type(a_coll[i])==type(coll_template[i])):
out_str = "TypeError:{} is not type {}"
raise TypeError(out_str.format(a_coll[i],type(coll_template[i])))
def clean_points(point_tup):
#Receives a tuple of tuples containing values and returns a new nested tuple with all 
#of the original tuples that contain exactly three numbers.
new_points = []
for point in point_tup:
try:
collection_check(point_tup[point],(0,0,0))
new_points.append(point[:])
except (TypeError,ValueError) as e:
print("Invalid Point! {}".format(point))
break
return list(new_points)
###    
#Test cases:
#   >>> clean_points(((1,2,3),(4,5,6),(7,8,9,10),('hi',2,3)))
#   Invalid Point! (7, 8, 9, 10)
#   Invalid Point! ('hi', 2, 3)
#   ((1, 2, 3), (4, 5, 6))
#   >>> clean_points((('h',0),(1,1,1),(2,2,2)))
#   Invalid Point! ('h', 0)
#   ((1, 1, 1), (2, 2, 2))
###

怎么回事？代码中还有其他问题需要解决，但这是我发现的第一个障碍。

Answer 1

修改代码以打印错误消息最终显示了您在标题中提到的错误消息：

def collection_check(a_coll, coll_template):
#Receives a collection to check and a template collection to check against.  The procedure
#raises errors if the collection to check is the incorrect type, is the wrong length, or 
#contains data types that do not match the data types of the provided template.
if not type(a_coll)==type(coll_template):
out_str = "TypeError:{} and template are different classes."
raise TypeError(out_str.format(a_coll))
if not(len(a_coll)==len(coll_template)):
out_str = "ValueError:{} and template are different lengths." 
raise ValueError(out_str.format(a_coll))
for i in range(len(a_coll)):
if not(type(a_coll[i])==type(coll_template[i])):
out_str = "TypeError:{} is not type {}"
raise TypeError(out_str.format(a_coll[i],type(coll_template[i])))
def clean_points(point_tup):
#Receives a tuple of tuples containing values and returns a new nested tuple with all 
#of the original tuples that contain exactly three numbers.
new_points = []
for point in point_tup:
try:
collection_check(point_tup[point],(0,0,0))
new_points.append(point[:])
except (TypeError,ValueError) as e:
print(e) # this will show the true error ========== right here 
print("Invalid Point! {}".format(point))
break
return list(new_points)

您正试图用tuple访问元组，这对python来说没有意义，因为您需要用整数索引访问元组。当像这样循环时

for point in point_tup:

点变量包含point_tup变量中的第i个元组，在测试用例之后，点在每次迭代中都将等于以下

(1, 2, 3)
(4, 5, 6)
(7, 8, 9, 10)
('hi', 2, 3)

所以你不需要像这个那样得到点元组

point_tup[point]

你已经在point变量中有了它

Answer 2

您的问题在于这些行：

for point in point_tup:
try:
collection_check(point_tup[point],(0,0,0))

point是一个元组(通过point_tup迭代而分配，而不是整数，因此您不能使用它来索引到point_tup。很可能您只想要collection_check(point, (0, 0, 0))。