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-rw-r--r--Doc/whatsnew/3.0.rst59
1 files changed, 42 insertions, 17 deletions
diff --git a/Doc/whatsnew/3.0.rst b/Doc/whatsnew/3.0.rst
index cf2caf2..afe842d 100644
--- a/Doc/whatsnew/3.0.rst
+++ b/Doc/whatsnew/3.0.rst
@@ -79,6 +79,48 @@ and fast errors; it's the subtle behavioral changes in code that
remains syntactically valid that trips people up. I'm also omitting
changes to rarely used features.)
+* The ``print`` statement has been replaced with a ``print()`` function,
+ with keyword arguments to replace most of the special syntax of the
+ old ``print`` statement (PEP 3105). Examples::
+
+ Old: print "The answer is", 2*2
+ New: print("The answer is", 2*2)
+
+ Old: print x, # Trailing comma suppresses newline
+ New: print(x, end=" ") # Appends a space instead of a newline
+
+ Old: print # Prints a newline
+ New: print() # You must call the function!
+
+ Old: print >>sys.stderr, "fatal error"
+ New: print("fatal error", file=sys.stderr)
+
+ Old: print (x, y) # prints repr((x, y))
+ New: print((x, y)) # Not the same as print(x, y)!
+
+ You can also customize the separator between items, e.g.::
+
+ print("There are <", 2**32, "> possibilities!", sep="")
+
+ which produces::
+
+ There are <4294967296> possibilities!
+
+ Notes about the ``print()`` function:
+
+ * The ``print()`` function doesn't support the "softspace" feature of
+ the old ``print`` statement. For example, in Python 2.x,
+ ``print "A\n", "B"`` would write ``"A\nB\n"``; but in Python 3.0,
+ ``print("A\n", "B")`` writes ``"A\n B\n"``.
+
+ * Initially, you'll be finding yourself typing the old ``print x``
+ a lot in interactive mode. Time to retrain your fingers to type
+ ``print(x)`` instead!
+
+ * When using the ``2to3`` source-to-source conversion tool, all
+ ``print`` statements are autmatically converted to ``print()``
+ function calls, so this is mostly a non-issue for larger projects.
+
* Python 3.0 uses strings and bytes instead of the Unicode strings and
8-bit strings. This means that pretty much all code that uses
Unicode, encodings or binary data in any way has to change. The
@@ -109,19 +151,6 @@ changes to rarely used features.)
* Code that unconditionally strips the trailing ``L`` from the ``repr()``
of a long integer will chop off the last digit instead.
-* The ``print()`` function doesn't support the "softspace" feature of
- the old ``print`` statement. For example, in Python 2.x,
- ``print "A\n", "B"`` would write ``"A\nB\n"``; but in Python 3.0,
- ``print("A\n", "B")`` writes ``"A\n B\n"``.
-
-* Also, ``print`` and ``print (x, y)`` behave differently without
- warning: the former used to add a newline in 2.x, but does nothing
- in 3.0; the latter used to print the ``repr()`` of a tuple in 2.x,
- but prints the individual values in 3.0.
-
-* You'll be finding yourself typing ``print x`` a lot in interactive
- mode. Time to retrain your fingers. :-)
-
Strings and Bytes
=================
@@ -241,10 +270,6 @@ language and built-in functions.
* PEP 3104: ``nonlocal`` statement. Using ``nonlocal x`` you can now
assign directly to a variable in an outer (but non-global) scope.
-* PEP 3105: ``print`` is now a function. Keyword arguments
- ``file=sys.stdout``, ``sep=" "`` and ``end="\n"`` let you customize
- it.
-
* PEP 3111: ``raw_input()`` renamed to ``input()``. That is, the new
``input()`` function reads a line from ``sys.stdin`` and returns it
with the trailing newline stripped. It raises ``EOFError`` if the