System2 to call Python2 and Python3 inside R

问题

I want to execute python with R but

> system2('python2', args =  c('-c', 'print', 'hello'), stdout = TRUE)
[1] ""

prints "" instead of hello with python2.

Then again

> system2('python3', args =  c('-c', 'print("hello")'), stdout = TRUE, stderr = TRUE)
sh: -c: line 0: syntax error near unexpected token `('
sh: -c: line 0: `'python3' -c print("hello") 2>&1'
character(0)
attr(,"status")
[1] 2
Warning message:
running command ''python3' -c print("hello") 2>&1' had status 2 

prints a lot of warnings. The intended output was hello.

How to print hello with python2/python3 inside R using system2?

来源：https://stackoverflow.com/questions/45426902/system2-to-call-python2-and-python3-inside-r