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…

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()…

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…

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…

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…

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…

There are already many ways to do the euclidean distance in python, you don't need to do it actually. But it is a very good exercise for programming as long…