Python代码片

1、matplotlib显示opencv图片

# -*- coding: utf-8 -*-
"""
Created on Fri Jun  5 16:18:07 2020

@author: shiruiyu
"""

import cv2 as cv
import matplotlib
import matplotlib.pyplot as plt



img = cv.imread("d:/lena.png", -1);
cv.imshow("img", img);

img_gray = cv.cvtColor(img, cv.COLOR_RGB2GRAY);
cv.imshow("img_gray", img_gray);

# 显示彩图， 
plt.subplot(121); plt.title("BGR2RGB"); 
plt.imshow(cv.cvtColor(img,cv.COLOR_BGR2RGB)); # 注意转换色彩次序

# 显示灰度图
plt.subplot(122);
plt.imshow(cv.cvtColor(img, cv.COLOR_RGB2GRAY), cmap = 'gray') #注意后面参数

效果图：

2、简单逐行写入文本

# Write your code here
i = 1
f = open("numbers.txt", "w")  # 利用追加模式,参数从w替换为a即可
b = 1.2341232131
while i <= 10:
    f.writelines(str(i) + str(' ') + str(b) + '
')
    i = i + 1

f.close()

文本内容如下：

1 1.2341232131
2 1.2341232131
3 1.2341232131
4 1.2341232131
5 1.2341232131
6 1.2341232131
7 1.2341232131
8 1.2341232131
9 1.2341232131
10 1.2341232131