Matplotlib: example will run on terminal but not when calling script

I'm trying to make an example bar graph using matplotlib. This is the script:

"""
====================
Horizontal bar chart
====================

This example showcases a simple horizontal bar chart.
"""
import matplotlib.pyplot as plt
plt.rcdefaults()
import numpy as np
import matplotlib.pyplot as plt


plt.rcdefaults()
fig, ax = plt.subplots()

# Example data
people = ('Tom', 'Dick', 'Harry', 'Slim', 'Jim')
y_pos = np.arange(len(people))
performance = 3 + 10 * np.random.rand(len(people))
error = np.random.rand(len(people))

ax.barh(y_pos, performance, xerr=error, align='center',
        color='green', ecolor='black')
ax.set_yticks(y_pos)
ax.set_yticklabels(people)
ax.invert_yaxis()  # labels read top-to-bottom
ax.set_xlabel('Performance')
ax.set_title('How fast do you want to go today?')

plt.show()

When I enter the code directly into the terminal it works, but when I try to call the script, I get this error:

Traceback (most recent call last):
  File "bargraph.py", line 2, in <module>
    import numpy as np
  File "/Users/MattBell/Desktop/numpy.py", line 2, in <module>
    import matplotlib.pyplot as plt
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/python/matplotlib/__init__.py", line 156, in <module>
    from matplotlib.cbook import is_string_like
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/python/matplotlib/cbook.py", line 29, in <module>
    import numpy.ma as ma
ImportError: No module named ma

I'm using OS X 10.10 and running python 2.7.