Using formatters to make string from dataframe

Question

I'm writing a string from a dataframe. I want it to respect formatters, but I don't want headers in the string. How can I get both of these things: no header, yes formatting?

import pandas
df = pandas.DataFrame({'c': 1, 'd': 2.3}, index=[0], )
formats = {'c': '{: 10d}', 'd': '{: 2.5f}'}
formatters = {k: v.format for k, v in formats.items()}
df.to_string(formatters=formatters, index=False, header=True)

u'c        d\n        1  2.30000'


df.to_string(formatters=formatters, index=False, header=False)

'1  2.30000'

I believe the expected result is something like this?:

'         1  2.30000'

Headers meaning? You don't want the `1 ` to be printed along? — void, Jun 28 '17 at 04:45
It seems to be only the leading empty characters that are removed. If filling with e.g. `0` it works, and also, the correct fractional part is retained. I also tried with multiple rows and it is only the first row that is affected. — JohanL, Jun 28 '17 at 04:56

score 1 · Accepted Answer · answered Jun 28 '17 at 04:47

1

[Disclaimer: I have never heard of DataFrame]

This just looks like a bug in DataFrame to me. Try reporting a bug to the developers.

As a workaround, it looks like you could just cut the first line off the string:

raw = df.to_string(formatters=formatters, index=False, header=True)
without_headers = '\n'.join(foo.splitlines()[1:])

answered Jun 28 '17 at 04:47

robru

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Uh, no? My code removes the first line, not the first character. – robru Jun 30 '17 at 19:59

score 0 · Answer 2 · answered Jun 28 '17 at 09:10

You could make a second DataFrame with everything formatted correctly

df2 = pd.DataFrame()
for col_name, col in df.iteritems():
    df2[col_name] = col.apply(lambda x: formats[col_name].format(x))

and then concatenate everything together

print(''.join(''.join(i[1:]) for i in df2.itertuples()))

'           1   2.30000'

Using formatters to make string from dataframe

2 Answers2

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