DataFrame处理

 ndarray转化为DataFrame

In：type(y）
Out：numpy.ndarray

from pandas import DataFrame
pre = DataFrame(y,columns=['pre'])

import pandas as pd
pre = pd.DataFrame(y,columns=['pre'])


In：type(pre)
Out：pandas.core.frame.DataFrame

在Dataframe中添加列

#添加空白列
df1['q'] = None
#添加所有值为1的列
df1['p'] = '1'

 Dataframe重置索引

import pandas as pd
#不保留原来索引
df_new = df.reset_index(drop=True)

#保留原来索引
df_new2 = df.reset_index()