Align 'assertEqual' output

[John A Meinel]

When using assertEqual on content that is a reasonable sized string, it is really nice to have the strings lined up vertically, to make it clear what bit does not match. Right now the output is:
reference = 'd\x00\x00\x000{"client_version": "0.0.1.dev.0", "request": "name"}d\x00\x00\x00\x08{"a": 1}'
actual = 'd\x00\x00\x004{"client_version": "0.0.1.dev.0", "request": "name"}d\x00\x00\x00\x08{"a": 1}'

Which makes it hard to see what byte is actually different. If you changed it to:
reference = 'd\x00\x00\x000{"client_version": "0.0.1.dev.0", "request": "name"}d\x00\x00\x00\x08{"a": 1}'
actual = 'd\x00\x00\x004{"client_version": "0.0.1.dev.0", "request": "name"}d\x00\x00\x00\x08{"a": 1}'

(You need a fixed width font, and not Launchpad's rendering of the above)

Then the columns match up and it is easy to detect the one character which is different.

[Robert Collins (lifeless)]

What John means is 'add some spaces after 'actual' to pad it the same length as reference.