comparing dictionaries

Christophe Delord christophe.delord at
Fri Aug 30 10:06:27 CEST 2002


If you have a recent version of Python, you can use list comprehension.
For example:

>>> A = {1:'a', 2:'b', 4:'d', 5:'e'}
>>> B = {2:'B', 3:'C', 5:'e'}

Entries in A and not in B are:

>>> [ k for k in A if k not in B ]
[1, 4]

The same way, entries in B and not in A are:

>>> [ k for k in B if k not in A ]

Entries that have different values in A and B are:

>>> [ k for k in A if k in B and A[k]!=B[k]]


On Fri, 30 Aug 2002 09:38:29 +0200
Oliver Eichler <oliver.eichler at> wrote:

> Hi 
> Is there an elegant way to compare dictionaries like:
> * What entries are in dictionary A and not in dictionary B
> * What entries are in dictionary B and not in dictionary A
> * What entries changed their values from A->B
> Oliver


(o_   Christophe Delord                   _o)
//\   /\\
V_/_  mailto:christophe.delord at   _\_V

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