Certain column formats break fixed-width lines (e.g. float format overflows).

[jkmacc-LANL]

...for example, you'd want '{0:11.7f}' to always return an 11-character string, but 11 is just a minimum width, per Python string formatting. Something like '{0:11.7f}'.format(1000.0000000) (e.g. a high sample rate) returns a 12-character string. The fix would have to be in pisces.schema.util.string_formatter .