Python Pandas v0.18+: is there a way to resample a dataframe without filling NAs?
Question: I wonder if there is a way to up resample a `DataFrame` without having to
decide how NAs should be filled immediately.

I tried the following but got the Future Warning:

> FutureWarning: .resample() is now a deferred operation use
> .resample(...).mean() instead of .resample(...)

Code:

    
    
    import pandas as pd
    dates = pd.date_range('2015-01-01', '2016-01-01', freq='BM')
    dummy = [i for i in range(len(dates))]
    df = pd.DataFrame({'A': dummy})
    df.index = dates
    df.resample('B')
    

**Is there a better way to do this, that doesn't show warnings?**

Thanks.


Answer: Use [`Resampler.asfreq`](http://pandas.pydata.org/pandas-
docs/stable/generated/pandas.tseries.resample.Resampler.asfreq.html):

    
    
    print (df.resample('B').asfreq())
                   A
    2015-01-30   0.0
    2015-02-02   NaN
    2015-02-03   NaN
    2015-02-04   NaN
    2015-02-05   NaN
    2015-02-06   NaN
    2015-02-09   NaN
    2015-02-10   NaN
    2015-02-11   NaN
    2015-02-12   NaN
    2015-02-13   NaN
    2015-02-16   NaN
    2015-02-17   NaN
    2015-02-18   NaN
    2015-02-19   NaN
    2015-02-20   NaN
    2015-02-23   NaN
    2015-02-24   NaN
    2015-02-25   NaN
    2015-02-26   NaN
    2015-02-27   1.0
    2015-03-02   NaN
    2015-03-03   NaN
    2015-03-04   NaN
    ...
    ...
    

