read_fwf: skip_blank_lines does nothing

Code Sample, a copy-pastable example if possible

from io import StringIO
import pandas as pd

f = StringIO('''A B

C D''')

df = pd.read_fwf(f, colspecs=[(0, 1), (2,3)], header=None, skip_blank_lines=True)
print(df)

Problem description

Output:

     0    1
0    A    B
1  NaN  NaN
2    C    D

The (second) blank line is not skipped, but instead there is a row with two NaN values. It seems that skip_blank_lines has no effect on read_fwf. On the other hand, read_csv(f, sep=' ', header=None), produces the expected output below.

Expected Output

   0  1
0  A  B
1  C  D

Output of pd.show_versions()

INSTALLED VERSIONS

commit: None python: 3.6.6.final.0 python-bits: 64 OS: Windows OS-release: 10 machine: AMD64 processor: Intel64 Family 6 Model 79 Stepping 1, GenuineIntel byteorder: little LC_ALL: None LANG: en_US.UTF-8 LOCALE: None.None

pandas: 0.23.1 pytest: 3.6.2 pip: 18.0 setuptools: 39.0.1 Cython: None numpy: 1.15.1 scipy: None pyarrow: None xarray: None IPython: 6.5.0 sphinx: 1.5.5 patsy: None dateutil: 2.7.3 pytz: 2018.5 blosc: None bottleneck: None tables: None numexpr: None feather: None matplotlib: None openpyxl: None xlrd: None xlwt: None xlsxwriter: None lxml: None bs4: None html5lib: 1.0.1 sqlalchemy: None pymysql: None psycopg2: None jinja2: 2.10 s3fs: None fastparquet: None pandas_gbq: None pandas_datareader: None

[jreback]

@dcdenu4 or anyone can submit a PR pandas is all volunteer and we have 3000+ open issues

[jnclt]

As mentioned above, the original issue isn’t reproducible anymore and there is a test covering this case (test_fwf_skip_blank_lines): https://github.com/pandas-dev/pandas/blob/36dcf519c67a8098572447f7d5a896740fc9c464/pandas/tests/io/parser/test_read_fwf.py#L354

As for read_csv, I think the behavior is as expected (Nan for coma-separated blank values).

I guess this issue can be closed?