You were already printing tuples. If you were not, then you are not now either.
To illustrate, your code would have to have been using print as if it was a function:
# Python 2
print(somestring)
which becomes, after translation
# Python 3
print((somestring))
That's not a tuple, that's just a pair of parentheses. It results in the same output on either version. In fact, 2to3 is smart enough to drop the inner parentheses again; the actual output written is simply
# Python 3
print(somestring)
However, if you were using multiple arguments in Python 2:
# Python 2
print(arg1, arg2)
then you'd already be printing a tuple, because that's really:
value_to_print = (arg1, arg2)
print value_to_print
So it would only be correct to preserve that behaviour in Python 3. If you see the 2to3 tool use print((....)), then it determined that you were already printing tuples.
Demo:
$ cat testprint.py
print('not a tuple')
print('two-value', 'tuple')
$ python2.7 testprint.py
not a tuple
('two-value', 'tuple')
$ 2to3 -w -f print testprint.py
RefactoringTool: Refactored testprint.py
--- testprint.py (original)
+++ testprint.py (refactored)
@@ -1,2 +1,2 @@
print('not a tuple')
-print('two-value', 'tuple')
+print(('two-value', 'tuple'))
RefactoringTool: Files that were modified:
RefactoringTool: testprint.py
$ python3.7 testprint.py
not a tuple
('two-value', 'tuple')
Note that this is different from using from __future__ import print_function in your Python 2 code, to disable the print statement and so making the code call the built-in print() function. The 2to3 tool already detects this case and will pass through print(...) function calls unchanged:
$ cat futureprint.py
from __future__ import print_function
print('not', 'a tuple')
$ python2.7 futureprint.py
not a tuple
$ 2to3 -w -f print futureprint.py
RefactoringTool: No files need to be modified.
$ python3.7 futureprint.py
not a tuple
You can force 2to3 to assume all your files use from __future__ import print_function, regardless, with the -p / --print-function command-line switch:
-p, --print-function Modify the grammar so that print() is a function
However, any deliberate print (tuple_element1, tuple_element2, ...) print statements would then be mis-translated as function calls:
$ cat printtuple.py
print ('two-value', 'tuple')
$ python2.7 printtuple.py
('two-value', 'tuple')
$ 2to3 -w -f print -p printtuple.py
RefactoringTool: No files need to be modified.
$ python3.7 printtuple.py
two-value tuple
