*Popen(["something"], shell=True)* works but it is similar to
*Popen(["something", "arg"], shell=True)* that passes "arg" to /bin/sh on POSIX systems instead of "something".

It is best to always use a string if `shell=True` is necessary.

It is a common confusion #20344, msg98732, #7839

http://stackoverflow.com/questions/21029154/understanding-python-subprocess-check-outputs-first-argument-and-shell-true
http://stackoverflow.com/questions/20787712/start-openoffice-process-with-python-to-use-with-pyuno-using-subprocess
http://stackoverflow.com/questions/17880847/python-subprocess-error-in-using-cp
http://stackoverflow.com/questions/17226912/why-does-simple-echo-in-subprocess-not-working
http://stackoverflow.com/questions/15109665/subprocess-call-using-string-vs-using-list
http://stackoverflow.com/questions/20128114/pythons-subprocess-does-not-interpret-as-expected-on-cygwin
http://stackoverflow.com/questions/16840427/python-on-linux-subprocess-popen-works-weird-with-shell-true
...

I've checked the same documentation patch applies to both default (3.5) and 2.7 branches.

There are no more instances of the misleading usage left (after applying the patch).

New changeset 5ef9a2c711f5 by R David Murray in branch '2.7':
#21347: use string not list in shell=True example.
http://hg.python.org/cpython/rev/5ef9a2c711f5

New changeset 3b27f3acf0c4 by R David Murray in branch '3.4':
#21347: use string not list in shell=True example.
http://hg.python.org/cpython/rev/3b27f3acf0c4

New changeset 217006c5455f by R David Murray in branch 'default':
Merge: #21347: use string not list in shell=True example.
http://hg.python.org/cpython/rev/217006c5455f

Thanks, Akira.