A simple function that takes a string representing an Indian phone number, and returns it in a canonical format '91dddddddddd'. Usage: >>> from parsephoneno import canonical_number >>> canonical_number('98220-12345') 919822012345 >>> canonical_number('98220 1234') Traceback (most recent call last): ... NumberTooShortError: 982201234 >>> phone_number('98220 1234') # Does not throw an exception >>> See docstrings for more examples