Pandas的数据清洗-,查看.isnull,.notnull(); .dropna(how = 'all',axis = 1, thresh = 2);.fillna(method)
http://liao.cpython.org/pandas20/http://liao.cpython.org/pandas21/构造一个NaN的dfval=np.arange(10,38).reshape(7,4)col='abcd'.split()idx='thisisjustafakepractisetoday'.split()df=pd.DataFrame(val,index=idx,c