Azure ML dataset: label column of dataset is None

Question

Hi,

For a project we need to load some data and its labels from an azure ML dataset. However when using the following sample code in python:

    from azureml.core import Workspace, Dataset
    subscription_id = 'sub-id...'
    resource_group = 'res-grp...'
    workspace_name = 'ws-name...'
    ds_name = 'name-of-ds'

    workspace = Workspace(subscription_id, resource_group, workspace_name)
    dataset = Dataset.get_by_name(workspace, name=ds_name).to_pandas_dataframe()

the labels are None. The dataset was exported from a "Image Classification Multi-label" project. For a dataset exported from a "Image Classification Multi-class" the code works fine. Currently I work on a local PC in Pycharm with Python 3.5 (due to easier debugging). Can you maybe help me with that?

Answer 1

@Daniel Here are the detailed steps to handle datasets with labels while loading to a pandas dataframe. For example:

import azureml.core  
import azureml.contrib.dataset  
from azureml.core import Dataset, Workspace  
from azureml.contrib.dataset import FileHandlingOption  
  
# get animal_labels dataset from the workspace  
animal_labels = Dataset.get_by_name(workspace, 'animal_labels')  
animal_pd = animal_labels.to_pandas_dataframe(file_handling_option=FileHandlingOption.DOWNLOAD, target_path='./download/', overwrite_download=True)  
  
import matplotlib.pyplot as plt  
import matplotlib.image as mpimg  
  
#read images from downloaded path  
img = mpimg.imread(animal_pd.loc[0,'image_url'])  
imgplot = plt.imshow(img)  

A sample notebook to try these scenarios is also available here. We hope this helps!!

Answer 2

@romungi-MSFT thanks for the answer! Actually I'm not trying to download the images but only get the labels with it's corresponding image_url's. When I use the sample code provided I get the following error:

TypeError: lstat: illegal type for path parameter  
During handling of the above exception, another exception occurred:  
azureml._common.exceptions.AzureMLException: AzureMLException:  
 Message: Execution failed in operation 'to_pandas_dataframe' for Dataset(id='subs_id...', name='ds_name...', version=1, exception_type=TypeError)  
 InnerException lstat: illegal type for path parameter  
 ErrorResponse   
{  
"error": {  
    "message": "Execution failed in operation 'to_pandas_dataframe' for Dataset(id='subs_id...', name='ds_name...', version=1, exception_type=TypeError)"  
}  

}

However the data gets downloaded to './download' but I still cant access the labels of the datapoints.