Packages, modules and exceptions

[Steve Purcell]

Ng Pheng Siong wrote:
> Within M2Crypto/SSL/Connection.py, I have "class Connection:..." Then, 
> within M2Crypto/SSL/__init__.py, I have "from Connection import
> Connection". This is so that clients can say "s = M2Crypto.SSL.Connection()"
> instead of "s = M2Crypto.SSL.Connection.Connection()".
> 
> Because of this, I can't just do "from M2Crypto.SSL import SSLError"
> within Connection.py. __init__.py's "from Connection import Connection"
> creates a circular reference.

You can. There is no problem with such a circular reference. Just try it out.

Consider the following files and their contents:

./M2Crypto/SSL/Connection.py
	#---------
	from M2Crypto.SSL import SSLError

	class Connection:
	    pass
	#---------
./M2Crypto/SSL/__init__.py
	#---------
	class SSLError(Exception):
	   pass

	from Connection import Connection
	#---------
./M2Crypto/__init__.py
	#---------
	#---------


I can start Python, and everything works as intended:

>>> from M2Crypto.SSL import Connection
>>> Connection
<class M2Crypto.SSL.Connection.Connection at 807f408>


Magic!


-Steve


-- 
Steve Purcell, Pythangelist
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