This one should be pretty simple, I hope.

Here's the constructor signature: def __init__(self, reason, resp=None, content=None):, which doesn't require resp to be defined, and I can see it is not defined most of the time, for example, in googleapiclient/http.py.

Then, given the representation method:

def __repr__(self): return '<BatchError %s "%s">' % (self.resp.status, self.reason) 

Which is also the string method:

__str__ = __repr__ 

This results in unprintable exceptions where resp is undefined, which is not very helpful when attempting to understand the error (e.g. #164).