print_stmt: "print" [ condition ("," condition)* [","] ]
print evaluates each condition in turn and writes the resulting
object to standard output (see below). If an object is not a string,
it is first converted to a string using the rules for string
conversions. The (resulting or original) string is then written. A
space is written before each object is (converted and) written, unless
the output system believes it is positioned at the beginning of a
line. This is the case: (1) when no characters have yet been written
to standard output; or (2) when the last character written to standard
output is \n; or (3) when the last write operation on standard
output was not a print statement. (In some cases it may be
functional to write an empty string to standard output for this
reason.)
A "\n" character is written at the end, unless the print
statement ends with a comma. This is the only action if the statement
contains just the keyword print.
Standard output is defined as the file object named stdout
in the built-in module sys. If no such object exists,
or if it is not a writable file, a RuntimeError exception is raised.
(The original implementation attempts to write to the system's original
standard output instead, but this is not safe, and should be fixed.)