Differences between revisions 1 and 3 (spanning 2 versions)
⇤ ← Revision 1 as of 2011-03-23 01:43:45 →
Size: 939
Editor: MichaelDroettboom
Comment:
← Revision 3 as of 2011-03-23 01:50:02 → ⇥
Size: 1021
Editor: MichaelDroettboom
Comment:
Deletions are marked like this. Additions are marked like this.
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- Easy things (that 2to3 handles pretty well): * Drop support for < 2.6 (master currently supports 2.4)
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  - print function * Easy things (that 2to3 handles pretty well):
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  - "in" vs. "has_key"   * print function
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  - "except Exception as exc" syntax   * "in" vs. "has_key"
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  - stdlib stuff   * "except Exception as exc" syntax
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- Unicode   * stdlib stuff
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  - Unicode literals by default * 2to3 is slooooow
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  - no implicit conversion between Unicode and bytes (encoding must be explicit) * Unicode
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  - files must have explicit Unicode encoding, or be binary -- hard to do both at same time   * Unicode literals by default
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- Exceptions   * no implicit conversion between Unicode and bytes (encoding must be explicit)

  * files must have explicit Unicode encoding, or be binary -- hard to do both at same time

* Exceptions
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- C/C++ issues * C/C++ issues
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  - For us, mostly hidden by using CXX   * For us, mostly hidden by using CXX
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  - PyCObject was dropped in Python 3.2 -- had to port CXX to use its replacement PyCapsule   * PyCObject was dropped in Python 3.2 -- had to port CXX to use its replacement PyCapsule

matplotlib's experiences porting to Python 3.

* Drop support for < 2.6 (master currently supports 2.4)

* Easy things (that 2to3 handles pretty well):

  • print function
  • "in" vs. "has_key"
  • "except Exception as exc" syntax
  • stdlib stuff

* 2to3 is slooooow

* Unicode

  • Unicode literals by default
  • no implicit conversion between Unicode and bytes (encoding must be explicit)
  • files must have explicit Unicode encoding, or be binary -- hard to do both at same time

* Exceptions 

  exceptions_found = []
  try:
      do_something()
  except Exception as e:
      exceptions_found.append(e)

Since e now has a traceback member, this creates a cycle e -> traceback -> current stack frame -> e. This cycle will keep alive all local variables in all frames beneath the source of the exception.

* C/C++ issues

  • For us, mostly hidden by using CXX

  • PyCObject was dropped in Python 3.2 -- had to port CXX to use its replacement PyCapsule