[問題] list[:] & list 差別
def _product_of_two_vectors_sample_(a, b):
if len(a[0]) != len(b):
return None
# Create the result matrix and fill it with zeros
output_list=[]
temp_row=len(b[0])*[0]
for r in range(len(a)):
-----> output_list.append(temp_row[:]) <-------------------???
for row_index in range(len(a)):
for col_index in range(len(b[0])):
sum=0
for k in range(len(a[0])):
sum=sum+a[row_index][k]*b[k][col_index]
output_list[row_index][col_index]=sum
return output_list
最近在自學
這邊有個問題一直不太懂
第8行的附加裡面的temp_row[:]和 output_list.append(temp_row)
之間有什麼不同
因為我自己會打temp_row
但是跑出來的結果是錯的
--
※ 發信站: 批踢踢實業坊(ptt.cc), 來自: 140.113.63.51
※ 文章網址: https://www.ptt.cc/bbs/Python/M.1459048662.A.3E6.html
推
03/27 11:25, , 1F
03/27 11:25, 1F
→
03/27 11:26, , 2F
03/27 11:26, 2F
→
03/27 11:26, , 3F
03/27 11:26, 3F
→
03/27 11:26, , 4F
03/27 11:26, 4F
→
03/27 11:26, , 5F
03/27 11:26, 5F
→
03/27 11:26, , 6F
03/27 11:26, 6F
→
03/27 11:26, , 7F
03/27 11:26, 7F
→
03/27 11:26, , 8F
03/27 11:26, 8F
→
03/27 11:26, , 9F
03/27 11:26, 9F
→
03/27 11:27, , 10F
03/27 11:27, 10F
→
03/27 11:29, , 11F
03/27 11:29, 11F
推
03/27 12:50, , 12F
03/27 12:50, 12F
→
03/27 13:58, , 13F
03/27 13:58, 13F
→
03/27 15:01, , 14F
03/27 15:01, 14F
→
03/27 15:02, , 15F
03/27 15:02, 15F
→
03/27 15:02, , 16F
03/27 15:02, 16F
→
03/28 01:32, , 17F
03/28 01:32, 17F
推
03/28 01:54, , 18F
03/28 01:54, 18F
→
03/28 02:08, , 19F
03/28 02:08, 19F