title: Google Colaboratory : Import Data, stack size exceeded?
body: <p>I am trying to import data form my folder with this code</p>
  
  <pre><code>from google.colab import files
  
  uploaded = files.upload()
  
  for fn in uploaded.keys():
    print('User uploaded file "{name}" with length {length} bytes'.format(name=fn, length=len(uploaded[fn])))
  </code></pre>
  
  <p>but it gives me this error :</p>
  
  <pre><code>Traceback (most recent call last) &lt;ipython-input-7-3ff52e25531b&gt; in &lt;module&gt;()
        1 from google.colab import files
        2 
  ----&gt; 3 uploaded = files.upload()
        4 
        5 #for fn in uploaded.keys():
  
  /usr/local/lib/python3.6/dist-packages/google/colab/files.py in upload()
       70     result = _output.eval_js(
       71         'google.colab._files._uploadFilesContinue("{output_id}")'.format(
  ---&gt; 72             output_id=output_id))
       73     if result['action'] != 'append':
       74       # JS side uses a generator of promises to process all of the files- some
  
  /usr/local/lib/python3.6/dist-packages/google/colab/output/_js.py in eval_js(script, ignore_result)
       37   if ignore_result:
       38     return
  ---&gt; 39   return _message.read_reply_from_input(request_id)
       40 
       41 
  
  /usr/local/lib/python3.6/dist-packages/google/colab/_message.py in read_reply_from_input(message_id, timeout_sec)
      104         reply.get('colab_msg_id') == message_id):
      105       if 'error' in reply:
  --&gt; 106         raise MessageError(reply['error'])
      107       return reply.get('data', None)
      108
  MessageError: RangeError: Maximum call stack size exceeded.
  </code></pre>
  
  <p>which I did not understand. is the reason the data relatively big (22578685bytes) or is it because of javascript?</p>