Notebook Issue In Google Colab

In the collab notebook here: https://colab.research.google.com/drive/1y0KnCFZvGVf_odSfcNAws6kcDD7HsI0L, refer to the sentencepice section. Defining the options dictionary using dict and then unpacking it results in TypeError: 'Dictionary' object is not callable

import sentencepiece as spm
import os

options = dict (
  # input spec
  input="toy.txt",
  input_format="text",
)

I fixed it using a normal dictionary.

options = {
  # input spec
  "input": "data.txt",
  "input_format": "text",
}

What could be the reason?