Calculating Savitsky-Golay filter coefficients - normalization
The SciPy library for scientific computing in Python contains functions for Savitzky-Golay filtering in its scipy.signal module since version 0.14.0, specifically you'll most likely be interested in the scipy.signal.savgol_coeffs function if you're only interested in the coefficients, or the scipy.signal.savgol_filter function which provides a nice interface for filtering alone.

When implementing some DSP method in Python, it's usually best to look into SciPy or scikits-* libraries rather than reinvent the wheel.