I see that I can plot in Python using either:
import matplotlib matplotlib.pyplot.plot(...)
import pylab pylab.plot(...)
Both of these use the same matplotlib plotting code.
So, which of these does the Python community recommend as the better method to plot? Why?
Both of those imports boil down do doing exactly the same thing and will run the exact same code, it is just different ways of importing the modules.
Also note that
matplotlib has two interface layers, a state-machine layer managed by
pyplot and the OO interface
pyplot is built on top of, see How can I attach a pyplot function to a figure instance?
pylab is a clean way to bulk import a whole slew of helpful functions (the
pyplot state machine function, most of
numpy) into a single name space. The main reason this exists (to my understanding) is to work with
ipython to make a very nice interactive shell which more-or-less replicates MATLAB (to make the transition easier and because it is good for playing around). See
At some level, this is purely a matter of taste and depends a bit on what you are doing.
If you are not embedding in a gui (either using a non-interactive backend for bulk scripts or using one of the provided interactive backends) the typical thing to do is
import matplotlib.pyplot as plt import numpy as np plt.plot(....)
which doesn’t pollute the name space. I prefer this so I can keep track of where stuff came from.
If you use
this is equivalent to running
from pylab import *
It is now recommended that for new versions of
ipython you use
which will set up all the proper background details to make the interactive backends to work nicely, but will not bulk import anything. You will need to explicitly import the modules want.
import numpy as np import matplotlib.pyplot as plt
is a good start.
If you are embedding
matplotlib in a gui you don’t want to import pyplot as that will start extra gui main loops, and exactly what you should import depends on exactly what you are doing.