How to input text file upload

[arissaizzati]

I want to able the user to upload text file using the ‘upload’. Then, the text file will be sent to my jupyter to do preprocessing and then return it back to anvil interface the output.

Here is my code in jupyter notebook:

import anvil.media

@anvil.server.callable

def sentence_tokenization(file):
    #with open(file) as f:
       #txt = f.read()
    with anvil.media.TempFile(file) as f:
        txt = f.read()
    from nltk.tokenize import sent_tokenize
    sentence_tokens = sent_tokenize(txt)
    return (sentence_tokens)

and here is my code in anvil:

def file_loader_1_change(self, file, **event_args):
    """This method is called when a new file is loaded into this FileLoader"""
    result = anvil.server.call('sentence_tokenization', file)

self.text_area_4.text = result

but i am getting this error after I upload the text file:

AttributeError: 'str' object has no attribute 'read' at <ipython-input-25-b2a2df1cab50>, line 9 called from [Form1, line 25](javascript:void(0))

This is my first time with anvil. It will help me a lot if anyone can help/guide me with this.
Thank you