错题本
报错信息:Cannot cast ufunc subtract output from dtype('float64') to dtype('int64') with casting rule 'same_kind'
输入的数据类型为浮点型,需要的数据类型是整形。
可以通过下面的语句完成类型转换
np.array(dta,dtype=np.float)
AttributeError: '_io.TextIOWrapper' object has no attribute 'xreadlines'
python 2 中有file.xreadlines(),作为一个迭代器,一次读取一行文件,在python3中已经移除,可使用file.readlines()代替
matrix 和 np.array 的逆
np.linalg.inv matrix.I
Open CV imwrite
cv.imwrite('filename', img)
OpenCv error: (-2) could not find a writer for the specified extension in function cv::imwrite_
filename 缺少拓展名
cv2.error: OpenCV(4.1.0) /io/opencv/modules/imgproc/src/resize.cpp:3718: error: (-215:Assertion failed) !ssize.empty() in function 'resize'
>>> img0 = cv2.imread('dir')
>>> img1 = img0[x0:x1, y0:y1, :]
>>> img2 = cv2.resize(img1, (128, 128))
cv2.error: OpenCV(4.1.0) /io/opencv/modules/imgproc/src/resize.cpp:3718: error: (-215:Assertion failed) !ssize.empty() in function 'resize'
这是由于img1的w,h为0导致的
注意处理img1时要满足(x0>x1)&(y0>y1)
否则会导致img.shape[:2]=(0,0)
can't assign to operator
变量名出错 a-b = np.load('a-b.npy') 改为 a_b = np.load('a-b.npy') + - / 之类operator不能用于变量名中 出现改错误应当检查变量名
AttributeError: 'ProgbarLogger' object has no attribute 'log_values'
generator 中没有传入样本