我对在 Python 中使用 CSV 函数比较陌生，需要您的帮助。
我有一个 python 程序，可以计算 opencv 中轮廓之间的距离以及角度，以后每次我按键盘上的 h 时，这些数据都会存储在 CSV 文件中。问题是，每次我按 h 时，较早的行都会被新行覆盖，而不是将其保存在新行中。有什么办法可以将新变量以 CSV 格式保存在新行中？
这是我的代码的一部分。整个代码很长，所以从它贴出必要的部分-
def calcDistHex(x6, y6, x5, y5, x4, y4, x3, y3, x2, y2, x, y):
dist1 = round(dist.euclidean((x6, y6), (x5, y5)))
dist2 = round(dist.euclidean((x5, y5), (x4, y4)))
dist3 = round(dist.euclidean((x4, y4), (x3, y3)))
dist4 = round(dist.euclidean((x3, y3), (x2, y2)))
dist5 = round(dist.euclidean((x2, y2), (x, y)))
dist6 = round(dist.euclidean((x, y), (x6, y6)))
#print(dist1)
cv2.putText(frame, str(dist1), (round(0.5 * x6 + 0.5 * x5), round(0.5 * y6 + 0.5 * y5)) , font, 0.5, (0, 0, 0), 1)
cv2.putText(frame, str(dist2), (round(0.5 * x5 + 0.5 * x4), round(0.5 * y5 + 0.5 * y4)) , font, 0.5, (0, 0, 0), 1)
cv2.putText(frame, str(dist3), (round(0.5 * x4 + 0.5 * x3), round(0.5 * y4 + 0.5 * y3)) , font, 0.5, (0, 0, 0), 1)
cv2.putText(frame, str(dist4), (round(0.5 * x3 + 0.5 * x2), round(0.5 * y3 + 0.5 * y2)) , font, 0.5, (0, 0, 0), 1)
cv2.putText(frame, str(dist5), (round(0.5 * x2 + 0.5 * x), round(0.5 * y2 + 0.5 * y)) , font, 0.5, (0, 0, 0), 1)
cv2.putText(frame, str(dist6), (round(0.5 * x + 0.5 * x6), round(0.5 * y + 0.5 * y6)) , font, 0.5, (0, 0, 0), 1)
pt6 = x6, y6
pt5 = x5, y5
pt4 = x4, y4
pt3 = x3, y3
pt2 = x2, y2
pt1 = x, y
m2 = gradient(pt2,pt1)
n2 = gradient(pt2,pt3)
if m2 is not None and n2 is not None:
angR2 = math.atan((n2-m2)/(1+(n2*m2)))
angD2 = math.degrees(angR2)
if math.isnan(angD2) is False:
cv2.putText(frame, str(round(abs(angD2))), (pt2[0]-40,pt2[1]-20), font, 1, (0, 0, 0))
#print(round(abs(angD2)),(pt1[0]-40,pt1[1]-20))
m3 = gradient(pt3,pt2)
n3 = gradient(pt3,pt4)
if m3 is not None and n3 is not None:
angR3 = math.atan((n3-m3)/(1+(n3*m3)))
angD3 = math.degrees(angR3)
if math.isnan(angD3) is False:
cv2.putText(frame, str(round(abs(angD3))), (pt3[0]-40,pt3[1]-20), font, 1, (0, 0, 0))
#print(round(abs(angD3)),(pt1[0]-40,pt1[1]-20))
m4 = gradient(pt4,pt3)
n4 = gradient(pt4,pt5)
if m4 is not None and n4 is not None:
angR4 = math.atan((n4-m4)/(1+(n4*m4)))
angD4 = math.degrees(angR4)
if math.isnan(angD4) is False:
cv2.putText(frame, str(round(abs(angD4))), (pt4[0]-40,pt4[1]-20), font, 1, (0, 0, 0))
#print(round(abs(angD4)),(pt1[0]-40,pt1[1]-20))
m5 = gradient(pt5,pt4)
n5 = gradient(pt5,pt6)
if m5 is not None and n5 is not None:
angR5 = math.atan((n5-m5)/(1+(n5*m5)))
angD5 = math.degrees(angR5)
if math.isnan(angD5) is False:
cv2.putText(frame, str(round(abs(angD5))), (pt5[0]-40,pt5[1]-20), font, 1, (0, 0, 0))
#print(round(abs(angD5)),(pt1[0]-40,pt1[1]-20))
m6 = gradient(pt6,pt5)
n6 = gradient(pt6,pt1)
if m6 is not None and n6 is not None:
angR6 = math.atan((n6-m6)/(1+(n6*m6)))
angD6 = math.degrees(angR6)
if math.isnan(angD6) is False:
cv2.putText(frame, str(round(abs(angD6))), (pt6[0]-40,pt6[1]-20), font, 1, (0, 0, 0))
#print(round(abs(angD6)),(pt1[0]-40,pt1[1]-20))
m = gradient(pt1,pt6)
n = gradient(pt1,pt2)
if m is not None and n is not None:
angR = math.atan((n-m)/(1+(n*m)))
angD = math.degrees(angR)
if math.isnan(angD) is False:
cv2.putText(frame, str(round(abs(angD))), (pt1[0]-40,pt1[1]-20), font, 1, (0, 0, 0))
#print(round(abs(angD)),(pt1[0]-40,pt1[1]-20))
if cv2.waitKey(1) == ord('h'):
timestamp = int(time.time() * 10000)
with open('dataset.csv', 'w', newline='') as dataset_file:
dataset = csv.DictWriter(
dataset_file,
["timestamp", "shape", "Side1", "Side2", "Side3", "Side4", "Side5", "Side6", "Perimeter", "Angle1", "Angle2", "Angle3", "Angle4", "Angle5", "Angle6", "AngleSum", "Error"]
)
dataset.writeheader()
dataset.writerow({
"timestamp": timestamp,
"shape": "Hexagon",
"Side1": dist1,
"Side2": dist2,
"Side3": dist3,
"Side4": dist4,
"Side5": dist5,
"Side6": dist6,
"Perimeter": (dist1 + dist2 + dist3 + dist4 + dist5 + dist6),
"Angle1": angD,
"Angle2": angD2,
"Angle3": angD3,
"Angle4": angD4,
"Angle5": angD5,
"Angle6": angD6,
"AngleSum": (angD + angD2 + angD3 + angD4 + angD5 + angD6),
"Error": "To Do"
})
return dist1, dist2, dist3, dist4, dist5, dist6, angD, angD2, angD3, angD4, angD5, angD6;
这是存储文件的定义函数。
此函数稍后在另一个循环中调用 -
if len(approx) == 6:
for j in n:
if(i % 2 == 0):
x6 = n[i - 10]
y6 = n[i - 9]
x5 = n[i - 8]
y5 = n[i - 7]
x4 = n[i - 6]
y4 = n[i - 5]
x3 = n[i - 4]
y3 = n[i - 3]
x2 = n[i - 2]
y2 = n[i - 1]
x = n[i]
y = n[i + 1]
#print(x, y, x2, y2, x3, y3, x4, y4)
string = str(x) + " " + str(y)
cv2.circle(frame, (x, y), 2, (0,0,100), 2)
cv2.putText(frame, string, (x, y), font, 0.5, (138, 138, 54), 2)
calcDistHex(x6, y6, x5, y5, x4, y4, x3, y3, x2, y2, x, y)
# text on remaining co-ordinates.
i = i + 1
cv2.imshow("Frame", frame)
cv2.imshow("Mask", threshold)
感谢任何帮助。用python编写。
答案 0 :(得分：-1)
尝试更改此行：
with open('dataset.csv', 'w', newline='') as dataset_file:
作者：
with open('dataset.csv', 'a', newline='') as dataset_file:
'w' 表示覆盖。 'a' 表示追加。更多信息：https://stackoverflow.com/a/1466036/3922534
编辑： 为避免每次写入时出现重复的标题，请删除该行：
dataset.writeheader()
从您当前的代码中，并在您的程序循环之前添加以下代码。它将通过用 CSV 标头覆盖文件来初始化文件（注意 'w' 模式），然后程序中的循环将只添加数据行。
with open('dataset.csv', 'w', newline='') as dataset_file:
dataset = csv.DictWriter(
dataset_file,
["timestamp", "shape", "Side1", "Side2", "Side3", "Side4", "Side5", "Side6", "Perimeter", "Angle1", "Angle2", "Angle3", "Angle4", "Angle5", "Angle6", "AngleSum", "Error"]
)
dataset.writeheader()