You have a file
/Users/marcholder/python/calendar.py
. I think this is your file and it is interfering with module with the same name calendar
from the Standard Library. Rename/remove that file.
If you can't explain it to a six year old, you don't understand it yourself, Albert Einstein
How to Ask Questions The Smart Way: link and another link
Create MCV example
Debug small programs
How to Ask Questions The Smart Way: link and another link
Create MCV example
Debug small programs