This page lists features that GvR has mentioned as goals for Python 3.0.

(Another list is at PythonThreeDotOh, but it incorporates items that GvR has never talked about.)

• Reduce feature duplication:
  • string module vs. string methods
  • xrange() vs range()
  • int vs. long
  • 8 bit vs. Unicode strings
  • map/filter/reduce vs. list comprehensions
  • lambda vs. def
• Library reorganization
• Return iterators instead of lists
  • d.keys(), .values(), .items()
  • range(), zip(), map(), filter()
• Consume iterators
  • min(), max()
• Optional static typing?
• Support only new-style classes; classic classes will be gone.

• Remove string exceptions, `x` for repr(x), sys.exc_type, coerce(), other deprecated stuff

• print as a function -- write(x,y,z), writeln(x,y,z)
• Do something so you can catch multiple exceptions using 'except E1, E2, E3:'. Maybe use 'except E1, E2, E3 as err:' if you want the error variable? (added by GvR, suggested by Bram Cohen).

See the "Python Regrets" talk and other recent presentations by Guido.

Other Ideas from the BDFL

• I want to reserve the leading dot for attribute assignment to a special object specified by a 'with' statement, e.g.

  with self:
      .foo = [1, 2, 3]
      .bar(4, .foo)

Rearrangements

intern(), id(): put in sys

xrange(): make range() return an iterator

buffer(): must die (use bytes, PEP 296)

raw_input(): use sys.stdin.readline()

input(): use eval(sys.stdin.readline())

callable(): just call it, already

execfile(), reload(): use exec()

compile(): put in sys

exec as a statement is not worth it -- make it a function

Dumb ideas

Other suggestions

GvR didn't pronounced on this

• lists:
  • remove the extend method: s+=x is equivalent to s.extend(x)
  • change parameters order of the insert method and make the index parameter optional so that the s.append method can be removed.

• remove the <> operator

• remove the is operator ?
• put the compile() function in its own module: on small interpreters, compiler support can be removed without changes to the core API.