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Yes, that does look like too much. My rationale for adding quotes around the value was in order to make it more clear in cases where the repr exceeds 100 characters. 
Instead of:
 Traceback (most recent call last):
 File "<stdin>", line 1, in <module>
 ValueError: [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 2 not in list
Have it clearly distinguished by using "":
 Traceback (most recent call last):
 File "<stdin>", line 1, in <module>
 ValueError: "[0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 2" not in list
I'm not sure if there's a trivial way to not display so many quotes in the case you supplied, you're better suited to decide if this can be done somehow.