Is print thread safe in Python (2.6/2.7)?

Question

Is print thread safe? That is, if I have two threads that each call print, say:

print "spam spam spam" # thread 1
print "eggs eggs eggs" # thread 2

I don't care which line prints first, but I do care if the two lines are mixed in together, something like this:

spam spaeggs eggs m seggspams

Does print perform its own locking to prevent this?

Answer 1

On Python 3, print is thread safe.

But Python 2 has broken scenario:

print "spam", "spam", "spam" # thread 1
print "eggs", "eggs", "eggs" # thread 2

In this case, 2 lines are mixed.

In your case, "spam spam spam" and "eggs eggs eggs" are not mixed, but newline is mixed like:

spam spam spameggs eggs eggs
eggs eggs eggsspam spam spam