How do I find the most frequently occuring element in an numpy arraylist in python-CodePudding

I have created a numpy arraylist from a CSV file that has a couple of thousand elements.

First, I used the np.array function to convert a dataframe column into an array.

Then I used a function that calculates the most common element in a list, but it gave me an error.

The code I wrote is shown below.

col_array = np.array(dataframe.col)

def most_common(lst): return max(set(lst), key=lst.count)

CodePudding user response：

For your most_common function, you need to cast the input to a list:

import numpy as np

def most_common(lst):
    lst = list(lst)
    return max(set(lst), key=lst.count)

col_array = np.array([0,0,1,1,1,3])
print(most_common(col_array))

There are many other solutions, see e.g.; Find the most frequent number in a NumPy array

CodePudding user response：

np.argmax(np.bincount(<np.array>))

just use np.bincount if your data values are not very large