在我对此numpy数组进行排序并删除所有重复的（y）值以及重复的（y）值的对应（x）值之后，我使用了for循环在其余坐标处绘制矩形。但是我得到了一个错误：ValueError：太多的值无法解包（预期2），但是它与原始形状相同，只是重复项已被删除。
from graphics import *
import numpy as np
def main():
win = GraphWin("A Window", 500, 500)
# starting array
startArray = np.array([[2, 1, 2, 3, 4, 7],
[5, 4, 8, 3, 7, 8]])
# the following reshapes the from all x's in one row and y's in second row
# to x,y rows pairing the x with corresponding y value.
# then it searches for duplicate (y) values and removes both the duplicate (y) and
# its corresponding (x) value by removing the row.
# then the unique [x,y]'s array is reshaped back to a [[x,....],[y,....]] array to be used to draw rectangles.
d = startArray.reshape((-1), order='F')
# reshape to [x,y] matching the proper x&y's together
e = d.reshape((-1, 2), order='C')
# searching for duplicate (y) values and removing that row so the corresponding (x) is removed too.
f = e[np.unique(e[:, 1], return_index=True)[1]]
# converting unique array back to original shape
almostdone = f.reshape((-1), order='C')
# final reshape to return to original starting shape but is only unique values
done = almostdone.reshape((2, -1), order='F')
# print all the shapes and elements
print("this is d reshape of original/start array:", d)
print("this is e reshape of d:\n", e)
print("this is f unique of e:\n", f)
print("this is almost done:\n", almostdone)
print("this is done:\n", done)
print("this is original array:\n",startArray)
# loop to draw a rectangle with each x,y value being pulled from the x and y rows
# says too many values to unpack?
for x,y in np.nditer(done,flags = ['external_loop'], order = 'F'):
print("this is x,y:", x,y)
print("this is y:", y)
rect = Rectangle(Point(x,y),Point(x+4,y+4))
rect.draw(win)
win.getMouse()
win.close()
main()
这是输出：
line 42, in main
for x,y in np.nditer(done,flags = ['external_loop'], order = 'F'):
ValueError: too many values to unpack (expected 2)
this is d reshape of original/start array: [2 5 1 4 2 8 3 3 4 7 7 8]
this is e reshape of d:
[[2 5]
[1 4]
[2 8]
[3 3]
[4 7]
[7 8]]
this is f unique of e:
[[3 3]
[1 4]
[2 5]
[4 7]
[2 8]]
this is almost done:
[3 3 1 4 2 5 4 7 2 8]
this is done:
[[3 1 2 4 2]
[3 4 5 7 8]]
this is original array:
[[2 1 2 3 4 7]
[5 4 8 3 7 8]]
为什么for循环适用于原始数组而不适用于这种排序的数组？ 还是我可以使用什么循环来仅使用（f），因为它已排序但shape（-1,2）？
我还尝试了一个不同的循环：
for x,y in done[np.nditer(done,flags = ['external_loop'], order = 'F')]:
哪个似乎可以解决太多的值错误，但是我得到了：
IndexError: index 3 is out of bounds for axis 0 with size 2
和
FutureWarning: Using a non-tuple sequence for multidimensional indexing is
deprecated; use `arr[tuple(seq)]` instead of `arr[seq]`. In the future this
will be interpreted as an array index, `arr[np.array(seq)]`, which will
result either in an error or a different result.
for x,y in done[np.nditer(done,flags = ['external_loop'], order = 'F')]:
我已经在stackexchange上进行了修复，但是无论我如何使用语法，都不断收到错误消息。
任何帮助将非常感谢！
答案 0 :(得分：0)
我没有graphics软件包（可能是Windows专用的东西？），但我确实知道您使此操作变得过于复杂。这是产生相同的done数组的更简单的版本：
from graphics import *
import numpy as np
# starting array
startArray = np.array([[2, 1, 2, 3, 4, 7],
[5, 4, 8, 3, 7, 8]])
# searching for duplicate (y) values and removing that row so the corresponding (x) is removed too.
done = startArray.T[np.unique(startArray[1,:], return_index=True)[1]]
for x,y in done:
print("this is x,y:", x, y)
print("this is y:", y)
rect = Rectangle(Point(x,y),Point(x+4,y+4))
rect.draw(win)
请注意，在以上版本的done.shape==(5, 2)中，而不是(2, 5)，但是您可以始终在for循环后使用done = done.T将其改回。
以下是您原始代码的一些注释，供以后参考：
order中的reshape标志与您的代码尝试执行的操作完全无关，并且使其变得更加混乱/潜在地增加了错误。没有它，您可以进行所有想要的重塑。
nditer的用例是一次迭代一个（或多个）数组的各个元素。通常，它不能用于遍历2D数组的行或列。如果尝试以这种方式使用它，则可能会得到错误的结果，该结果高度依赖于内存中数组的布局（如您所见）。
要迭代2D数组的行或列，只需使用简单的迭代即可。如果仅遍历数组（例如for row in arr:），则会得到每一行，一次一行。如果要使用列，则可以先转置数组（就像我在上面的代码中使用.T所做的那样）。
.T .T进行数组的转置。例如，如果您以
arr = np.array([[0, 1, 2, 3],
[4, 5, 6, 7]])
然后转置为：
arr.T==np.array([[0, 4],
[1, 5],
[2, 6],
[3, 7]])