How to create a dict based on such a file?

[Wang Coeus]

Hi all,
I am new to python. Currently I encountered a problem, please help me to
solve this. Thanks in advance!
I have a file like below:
++++++++++++++++++++++++++++++++++++++
block1
{
  key1=value1
  key2=value2
  key3=value3
}
block2
{
  key1=value4
  key2=value5
  key4=value6
}
...
blockn
{
  key1=value7
  key2=value8
  keyn=valuen
}
+++++++++++++++++++++++++++++++++++++++
Different block may have different keys and even same key in different
blocks may have different values.

Now I want to get a function, which like this:
func(key)
and it will return a dictionary as below:
func(key1) = [block1:value1,block2:value4,...,blockn:value7]
and if one block has no "key1" parameter, it will not include in this
dict.

Thanks a lot!
-- 
Coeus
In the middle of every difficulty lies opportunity.
		-- Albert Einstein