read_csv not respecting MultiIndex names

[toobaz]

Code Sample, a copy-pastable example if possible

In [2]: pd.read_csv('/tmp/csv.csv', header=None)
Out[2]: 
   0  1  2
0  0  2  2
1  1  2  2
2  2  2  2

In [3]: mi = pd.MultiIndex.from_tuples([(1,2), (3,4)], names=['l1', 'l2'])

In [4]: pd.read_csv('/tmp/csv.csv', header=None, names=mi)
Out[4]: 
   1  3
   2  4
0  2  2
1  2  2
2  2  2

Expected Output

In [4]: pd.read_csv('/tmp/csv.csv', header=None, names=mi)
Out[4]: 
l1  1  3
l2  2  4
0   2  2
1   2  2
2   2  2

Might be worth fixing together with #7589 (just a rough guess, didn't look at the code)

output of pd.show_versions()

In [8]: pd.show_versions()

INSTALLED VERSIONS
------------------
commit: eba78032e927d2680850c88190f3bafe18cac6ba
python: 3.4.3.final.0
python-bits: 64
OS: Linux
OS-release: 4.3.0-1-amd64
machine: x86_64
processor: 
byteorder: little
LC_ALL: None
LANG: it_IT.utf8

pandas: 0.18.0rc1+66.geba7803
nose: 1.3.6
pip: 1.5.6
setuptools: 20.1.1
Cython: 0.23.2
numpy: 1.10.0.post2
scipy: 0.16.0
statsmodels: 0.8.0.dev0+755fa81
xarray: None
IPython: 4.1.1
sphinx: 1.3.1
patsy: 0.3.0-dev
dateutil: 2.4.2
pytz: 2015.6
blosc: None
bottleneck: None
tables: 3.2.2
numexpr: 2.4.3
matplotlib: 1.5.dev1
openpyxl: None
xlrd: 0.9.4
xlwt: None
xlsxwriter: 0.7.3
lxml: None
bs4: 4.4.0
html5lib: 0.999
httplib2: 0.9.1
apiclient: None
sqlalchemy: 1.0.11
pymysql: None
psycopg2: None
jinja2: 2.8

[jreback]

you need to specify a list for the header, see http://pandas.pydata.org/pandas-docs/stable/io.html#reading-columns-with-a-multiindex

[jreback]

in the future pls supply examples as copy-pastable (use StringIO)

[toobaz]

Sorry, the example could have also been simpler:

In [3]: mi = pd.MultiIndex.from_tuples([(1,2), (3,4)], names=['l1', 'l2'])

In [4]: pd.read_csv(StringIO('0,2,2\n1,2,2\n2,2,2'), names=mi)
Out[4]: 
   1  3
   2  4
0  2  2
1  2  2
2  2  2

(the problem did not lie in header)

[toobaz]

(... which means that this is a bug, I think)

[jreback]

@toobaz that does't make any sense

names : array-like, default None
    List of column names to use. If file contains no header row, then you
    should explicitly pass header=None

what you are writing doesn't match the doc-string, nor the expected behavior.

[toobaz]

Ooops, right, sorry. Too bad.