ImportError: No module named pymc3

Question

I am trying to run the following example:

import pymc3 as pm

from numpy import array, empty

from numpy.random import randint

__all__ = [
    'disasters_array',
    'switchpoint',
    'early_mean',
    'late_mean',
    'rate',
    'disasters']

disasters_array = array([4, 5, 4, 0, 1, 4, 3, 4, 0, 6, 3, 3, 4, 0, 2, 6,
                         3, 3, 5, 4, 5, 3, 1, 4, 4, 1, 5, 5, 3, 4, 2, 5,
                         2, 2, 3, 4, 2, 1, 3, 2, 2, 1, 1, 1, 1, 3, 0, 0,
                         1, 0, 1, 1, 0, 0, 3, 1, 0, 3, 2, 2, 0, 1, 1, 1,
                         0, 1, 0, 1, 0, 0, 0, 2, 1, 0, 0, 0, 1, 1, 0, 2,
                         3, 3, 1, 1, 2, 1, 1, 1, 1, 2, 4, 2, 0, 0, 1, 4,
                         0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 1, 0, 1])


switchpoint = DiscreteUniform(
    'switchpoint',
    lower=0,
    upper=110,
    doc='Switchpoint[year]')
early_mean = Exponential('early_mean', beta=1.)
late_mean = Exponential('late_mean', beta=1.)


@deterministic(plot=False)
def rate(s=switchpoint, e=early_mean, l=late_mean):
    ''' Concatenate Poisson means '''
    out = empty(len(disasters_array))
    out[:s] = e
    out[s:] = l
    return out

disasters = Poisson('disasters', mu=rate, value=disasters_array, observed=True)

When I run it, it throws the following error: ImportError: No module named pymc3

I have installed pymc3 with pip and it was successful. I don't know why it can't find pymc3. Does anybody know how to solve this? I've used several editors, and none of them is working.

Thanks!

Answer 1

You likely have more than one python interpreter installed. Or there are more virtual environments.

You installed pymc3 in one and your script runs with another.