python空心矩形
时间: 2023-11-01 14:57:26 浏览: 55
您好!以下是一个用 Python 语言打印空心矩形的示例代码:
```python
def print_hollow_rectangle(width, height):
for i in range(height):
for j in range(width):
if i == 0 or i == height - 1 or j == 0 or j == width - 1:
print("*", end="")
else:
print(" ", end="")
print()
# 示例调用
print_hollow_rectangle(5, 4)
```
输出结果:
```
*****
* *
* *
*****
```
相关问题
python opencv 如何识别空心矩形定位点
要使用Python的OpenCV库来识别空心矩形定位点,可以按照以下步骤进行操作:
1. 导入所需的库:
```python
import cv2
import numpy as np
```
2. 读取图像并转换为灰度图像:
```python
image = cv2.imread("image.jpg")
gray = cv2.cvtColor(image, cv2.COLOR_BGR2GRAY)
```
3. 进行边缘检测:
```python
edges = cv2.Canny(gray, 50, 150)
```
4. 执行轮廓检测:
```python
contours, _ = cv2.findContours(edges, cv2.RETR_EXTERNAL, cv2.CHAIN_APPROX_SIMPLE)
```
5. 遍历检测到的轮廓并筛选出空心矩形:
```python
for contour in contours:
approx = cv2.approxPolyDP(contour, 0.01 * cv2.arcLength(contour, True), True)
if len(approx) == 4:
cv2.drawContours(image, [approx], 0, (0, 255, 0), 2)
```
6. 显示结果:
```python
cv2.imshow("Result", image)
cv2.waitKey(0)
cv2.destroyAllWindows()
```
请注意,这是一个基本的示例代码,你可能需要根据实际情况进行调整和优化。此外,确保图像中的矩形是明显可见且不重叠的。
python输出一个空心矩形,给出代码
使用python绘制空心矩形的代码如下:from turtle import *forward(150)
right(90)
forward(75)
right(90)
forward(150)
right(90)
forward(75)up()
forward(30)
down()right(90)
forward(150)
right(90)
forward(75)
right(90)
forward(150)
right(90)
forward(75)done()