print() is a function in Python 3

[cclauss]

flake8 testing of https://github.com/CamDavidsonPilon/Probabilistic-Programming-and-Bayesian-Methods-for-Hackers on Python 3.7.0

$ flake8 . --count --select=E901,E999,F821,F822,F823 --show-source --statistics

./Chapter3_MCMC/github_pull.py:78:28: E999 SyntaxError: invalid syntax
    print " -------------- "
                           ^
./sandbox/Chapter10_/github_datapull.py:16:55: E999 SyntaxError: invalid syntax
    print "Scrapping data from Github. Sorry Github..."
                                                      ^
./Chapter2_MorePyMC/daft_plot.py:9:41: E999 SyntaxError: invalid syntax
    print "python library Daft required."
                                        ^
3     E999 SyntaxError: invalid syntax
3