BUG: DataFrame.to_string() creates extra space for string dtypes · Issue #4158 · pandas-dev/pandas (original) (raw)

pd.__version__
'0.12.0.dev-6a0b9ec'

exdf = pd.DataFrame([["aoe",12,3.14],["qjk",34,5.67]]) exdf.columns = list('abc') #exdf = exdf.reindex(columns=reversed(list('abc'))) def a(inp): return '{:>3s},'.format(inp) def b(inp): return '{:2d},'.format(inp) def c(inp): return '{:3.2f},'.format(inp) print repr(exdf.to_string(formatters={'a':a,'b':b,'c':c}, index=False,header=False))

' aoe, 12, 3.14,\n qjk, 34, 5.67,'
^^extra space!

Note, when you reindex the columns to be the other way around by removing the # in front of the line exdf = exdf.reindex ... then you get:

'3.14, 12, aoe,\n5.67, 34, qjk,'
^^no extra space!

where one can easily see, that usually, as it is correct, the first element in the line does NOT get a space. Therefore I consider this a formatting bug for (string) objects.