Python error "import: unable to open X server"

those are errors from your command shell. you are running code through the shell, not python.

try from a python interpreter ;)

$ python
Python 2.7.5+ (default, Sep 19 2013, 13:48:49) 
[GCC 4.8.1] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import requests
>>> from datetime import datetime,date,timedelta
>>> 
>>> now = datetime.now()
>>> 

if you are using a script, you may invoke directly with python:

$ python mixcloud.py

otherwise, ensure it starts with the proper shebang line:

#!/usr/bin/env python

... and then you can invoke it by name alone (assuming it is marked as executable):

$ ./mixcloud.py

Check whether your #! line is in the first line of your python file. I got this error because I put this line into the second line of the file.