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This topic created in 3250 days ago, the information mentioned may be changed or developed.
t = {}
t['a'] = 'A'
t['b'] = 'B'
t['c'] = 'C'
for k, v in t.items():
print(v)
这个代码 j 结果在 py2.7 中是 ACB, 在 py3.6 中是 ABC.
而且我试了好多次 py3.6 的字典输出顺序跟存入顺序一样啊
t['a'] = 'A'
t['b'] = 'B'
t['c'] = 'C'
for k, v in t.items():
print(v)
这个代码 j 结果在 py2.7 中是 ACB, 在 py3.6 中是 ABC.
而且我试了好多次 py3.6 的字典输出顺序跟存入顺序一样啊
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1
AX5N Jun 9, 2017
3.6 开始是有序的，之前是无序的
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2
Douglee Jun 9, 2017
那还要 collections.OrderedDict 有什么用..
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3
jimmyye Jun 9, 2017
https://docs.python.org/3.6/whatsnew/3.6.html#new-dict-implementation
> The order-preserving aspect of this new implementation is considered an implementation detail and should not be relied upon (this may change in the future, but it is desired to have this new dict implementation in the language for a few releases before changing the language spec to mandate order-preserving semantics for all current and future Python implementations; this also helps preserve backwards-compatibility with older versions of the language where random iteration order is still in effect, e.g. Python 3.5). |
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4
264768502 Jun 9, 2017 via Android
兼容性考虑
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5
laoyuan Jun 9, 2017
这个“序”如何访问呢？
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6
laoyuan Jun 9, 2017
如何根据序来访问呢？
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7
ipwx Jun 9, 2017
想要有序，请使用 collections.OrderedDict
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8
dd99iii Jun 9, 2017
t = {}
t['b'] = 'B' t['a'] = 'A' t['c'] = 'C' for k, v in t.items(): print(v) 输出顺序跟存入顺序一样？你再试试 |
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9
lrxiao Jun 10, 2017
3.6 确保 dict 有序。。。但是你不能把这个当确保的事情
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10
lrxiao Jun 10, 2017
第一个确保 -> 实现
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11
zonghua Jun 10, 2017 via iPhone
tablib 里面用的好多
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13
dd99iii Jun 11, 2017
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