FAQ: __str__ vs __repr__

[Andreas Kostyrka]

Well, It means that eval(repr(x)) == x if at all possible.
Basically:
repr('abc') -> 'abc'
str('abc') -> abc

You'll notice that 'abc' is a valid python expression for the string,
while abc is not a valid string expression.

Andreas

On Wed, Jun 15, 2005 at 02:46:04PM +0200, Jan Danielsson wrote:
>   Sorry, but I Just Don't Get It. I did search the 'net, I did read the
> FAQ, but I'm too dumb to understand.
> 
>    As far as I can gather, __str__ is just a representation of the
> object. For instance:
> 
> class ServerConnection:
>    def __str__(self):
>       buf = "Server: " + self.name + "\n"
>       buf += "Sent bytes: " + str(self.sentBytes) + "\n"
>       buf += "Recv bytes: " + str(self.recvBytes) + "\n"
>       return buf
> 
>    However, I don't understand what __repr__ should be. There's a phrase
> in the documentation which makes it highly confusing for a beginner like
> me: "If at all possible, this should look like a valid Python expression
> that could be used to recreate an object with the same value (given an
> appropriate environment).". What does that mean? Does it mean that I
> should return:
> 
>    def __str__(self):
>       buf = "self.name=" + self.name + "\n"
>       buf += "self.sentBytes=" + str(self.sentBytes) + "\n"
>       buf += "self.recvBytes=" + str(self.recvBytes) + "\n"
>       return buf
> 
>    ..or is there some other "valid Python expression" format which I
> have yet to encounter?
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