Tukey five number summary in Python

Question

I have been unable to find this function in any of the standard packages, so I wrote the one below. Before throwing it toward the Cheeseshop, however, does anyone know of an already published version? Alternatively, please suggest any improvements. Thanks.

def fivenum(v):
    """Returns Tukey's five number summary (minimum, lower-hinge, median, upper-hinge, maximum) for the input vector, a list or array of numbers based on 1.5 times the interquartile distance"""
    import numpy as np
    from scipy.stats import scoreatpercentile
    try:
        np.sum(v)
    except TypeError:
        print('Error: you must provide a list or array of only numbers')
    q1 = scoreatpercentile(v,25)
    q3 = scoreatpercentile(v,75)
    iqd = q3-q1
    md = np.median(v)
    whisker = 1.5*iqd
    return np.min(v), md-whisker, md, md+whisker, np.max(v),

Answer 1

I would get rid of these two things:

import numpy as np
from scipy.stats import scoreatpercentile

You should be importing at the module level. This means that users will be aware of missing dependencies as soon as they import your module, rather than when they call the function.

try:
    sum(v)
except TypeError:
    print('Error: you must provide a list or array of only numbers')

Several problems with this:

1. Don't type check in Python. Document what the function takes.
2. How do you know callers will see this? They might not be running at a console, and even if they are, they might not want your error message interfering with their output.
3. Don't type check in Python.

If you do want to raise some sort of exception for invalid data (not type checking), either let an existing exception propagate, or wrap it in your own exception type.