diff options
Diffstat (limited to 'Lib/pickle.py')
| -rw-r--r-- | Lib/pickle.py | 20 |
1 files changed, 12 insertions, 8 deletions
diff --git a/Lib/pickle.py b/Lib/pickle.py index da7bdb6..45bc38c 100644 --- a/Lib/pickle.py +++ b/Lib/pickle.py @@ -167,25 +167,29 @@ del x class Pickler: - def __init__(self, file, proto=1): + def __init__(self, file, proto=0): """This takes a file-like object for writing a pickle data stream. The optional proto argument tells the pickler to use the given protocol; supported protocols are 0, 1, 2. The default - protocol is 1 (in previous Python versions the default was 0). + protocol is 0, to be backwards compatible. (Protocol 0 is the + only protocol that can be written to a file opened in text + mode and read back successfully.) Protocol 1 is more efficient than protocol 0; protocol 2 is - more efficient than protocol 1. Protocol 2 is not the default - because it is not supported by older Python versions. + more efficient than protocol 1. - XXX Protocol 2 is not yet implemented. + Specifying a negative protocol version selects the highest + protocol version supported. The file parameter must have a write() method that accepts a single string argument. It can thus be an open file object, a StringIO object, or any other custom object that meets this interface. """ - if proto not in (0, 1, 2): + if proto < 0: + proto = 2 + elif proto not in (0, 1, 2): raise ValueError, "pickle protocol must be 0, 1 or 2" self.write = file.write self.memo = {} @@ -1455,10 +1459,10 @@ try: except ImportError: from StringIO import StringIO -def dump(obj, file, proto=1): +def dump(obj, file, proto=0): Pickler(file, proto).dump(obj) -def dumps(obj, proto=1): +def dumps(obj, proto=0): file = StringIO() Pickler(file, proto).dump(obj) return file.getvalue() |