If you want to read an image, you will need the ‘image’ package: import Image read the image: Image.open(filename) convert the Image to grey scale: Image.open(filename).convert(‘L’) convert the image to array: numpy.asarray(Image.open(filename).convert(‘L’)) Notice: Here is a introduction to “Image” package…
I have a list and I want to get the rank for each member. This is important for many data mining algorithm, for example kNN (k-Nearest-Neighbor), you want to know the rank of a certain record. For example: myList =…
There are many ways to sort a 2d arrays. In general, you can use the sorted(), np.array.sort(),… But you should also understand what is meaning of list1.sort(list2) ravel() vs. flatten() what return the key function back in sorted() what will…
I just want to reshape the List without use the numpy, so I found a piece of crazy code in stackoverflow: output: [(‘a’, ‘b’), (‘c’, ‘d’), (‘e’, ‘f’)] After the long consideration, I understand the code at last. The python…
Asterik in python is usually very confused for the beginner. Some times it appears one time before a variable like *args, some times it appears two times like **args. Usually it appears in function definition: * and ** allow arbitrary…
In data mining tasks is the attributes normalizing usually a prerequisite in order to get a meaningful result. For example, if you want to calculate the euclidean distance, the attributes with relative large numerical values will have more influence of…
If you copy a bundle of python codes into eclipse, usually the pydev can not find the paths. In this case, you have 2 two ways to deal with this problem. right click the folder -> pydev -> Set as…
