mirror of https://github.com/jab/bidict.git
32 lines
1.4 KiB
PHP
32 lines
1.4 KiB
PHP
|
Order Matters
|
||
|
|
+++++++++++++
|
||
|
|
|
||
|
|
Performing a bulk insert operation
|
||
|
|
(e.g. on initialization or
|
||
|
|
via :func:`update() <bidict.bidict.update>`,
|
||
|
|
:func:`forceupdate() <bidict.bidict.forceupdate>`,
|
||
|
|
or :func:`putall() <bidict.bidict.putall>`),
|
||
|
|
is like performing a sequence of single insert operations
|
||
|
|
for each of the provided items
|
||
|
|
(with the advantage that the bulk insert fails clean, i.e. if it fails,
|
||
|
|
it will be as if none of the single insert operations were ever called).
|
||
|
|
Therefore, the order of the items provided to the bulk insert operation
|
||
|
|
may affect the result::
|
||
|
|
|
||
|
|
>>> from bidict import bidict
|
||
|
|
>>> b = bidict({0: 0, 1: 2})
|
||
|
|
>>> b.forceupdate([(2, 0), (0, 1), (0, 0)])
|
||
|
|
>>> # 1. (2, 0) overwrites (0, 0) -> bidict({2: 0, 1: 2})
|
||
|
|
>>> # 2. (0, 1) is added -> bidict({2: 0, 1: 2, 0: 1})
|
||
|
|
>>> # 3. (0, 0) overwrites (0, 1) and (2, 0) -> bidict({0: 0, 1: 2})
|
||
|
|
>>> sorted(b.items())
|
||
|
|
[(0, 0), (1, 2)]
|
||
|
|
>>> b = bidict({0: 0, 1: 2}) # as before
|
||
|
|
>>> # Give same items to forceupdate() but in a different order:
|
||
|
|
>>> b.forceupdate([(0, 1), (0, 0), (2, 0)])
|
||
|
|
>>> # 1. (0, 1) overwrites (0, 0) -> bidict({0: 1, 1: 2})
|
||
|
|
>>> # 2. (0, 0) overwrites (0, 1) -> bidict({0: 0, 1: 2})
|
||
|
|
>>> # 3. (2, 0) overwrites (0, 0) -> bidict({1: 2, 2: 0})
|
||
|
|
>>> sorted(b.items()) # different result
|
||
|
|
[(1, 2), (2, 0)]
|