All input arrays must have the same shape ValueError.?

#===================================================== Snippet 1 =======================================

%matplotlib inline

import os
import random

import imageio
import pandas as pd
from scipy.misc import imread

import numpy as np
import matplotlib.pyplot as plt
import matplotlib.image as mpimg

#===================================================== Snippet 2 =======================================

# Then I loaded the csv files, so that it would be easier to locate the files

root_dir = os.path.abspath('.')
data_dir = '/Users/renedena/Documents/Machine_Learning_Project_II/all'

#print(root_dir)


train = pd.read_csv(os.path.join(data_dir, 'train.csv'))
test = pd.read_csv(os.path.join(data_dir, 'test.csv'))


#===================================================== Snippet 3(issue found here) ======================

# I first load all the images and "TRY" to resize them into a single numpy array

#from scipy.misc import imresize
import skimage.transform

# Code to resizing all Train images first
temp = []
for img_name in train.Id:
    img_path = os.path.join(data_dir, 'train', img_name)
    img = imageio.imread(img_path)
    img = skimage.transform.resize(img, (32, 32), mode='constant') # mode='reflect'
    img = img.astype('float32') # this will help us in later stage
    temp.append(img)
train_x = np.stack(temp)

#____________________________________________________________________________________________________________
#++++++++++++++++++++^^^^^^^Like i mentioned, this is where im getting my error ^^^^^^+++++++++++++++++++++++
##++++++++++++++++++++++++++++ The output im getting is as follows: +++++++++++++++++++++++++++++++++++++++++
#____________________________________________________________________________________________________________

#Output below:

---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
<ipython-input-7-60df81a21aae> in <module>()
     21     temp.append(img)
     22 print(len(temp))
---> 23 train_x = np.stack(temp)
     24 print(len(train_x))

~/anaconda3/lib/python3.6/site-packages/numpy/core/shape_base.py in stack(arrays, axis, out)
    351     shapes = set(arr.shape for arr in arrays)
    352     if len(shapes) != 1:
--> 353         raise ValueError('all input arrays must have the same shape')
    354
    355     result_ndim = arrays[0].ndim + 1

ValueError: all input arrays must have the same shape