ValueError: setting an array element with a sequence

Question

This Python code:

import numpy as p

def firstfunction():
    UnFilteredDuringExSummaryOfMeansArray = []
    MeanOutputHeader=[\'TestID\',\'         


        

Answer 1

From the code you showed us, the only thing we can tell is that you are trying to create an array from a list that isn't shaped like a multi-dimensional array. For example

numpy.array([[1,2], [2, 3, 4]])

or

numpy.array([[1,2], [2, [3, 4]]])

will yield this error message, because the shape of the input list isn't a (generalised) "box" that can be turned into a multidimensional array. So probably UnFilteredDuringExSummaryOfMeansArray contains sequences of different lengths.

Edit: Another possible cause for this error message is trying to use a string as an element in an array of type float:

numpy.array([1.2, "abc"], dtype=float)

That is what you are trying according to your edit. If you really want to have a NumPy array containing both strings and floats, you could use the dtype object, which enables the array to hold arbitrary Python objects:

numpy.array([1.2, "abc"], dtype=object)

Without knowing what your code shall accomplish, I can't judge if this is what you want.

Answer 2

In my case, I had a nested list as the series that I wanted to use as an input.

First check: If

df['nestedList'][0]

outputs a list like [1,2,3], you have a nested list.

Then check if you still get the error when changing to input df['nestedList'][0].

Then your next step is probably to concatenate all nested lists into one unnested list, using

[item for sublist in df['nestedList'] for item in sublist]

This flattening of the nested list is borrowed from How to make a flat list out of list of lists?.