declare a dataframe code example

Example 1: create dataframe with column names pandas

In [4]: import pandas as pd
In [5]: df = pd.DataFrame(columns=['A','B','C','D','E','F','G'])
In [6]: df
Out[6]:
Empty DataFrame
Columns: [A, B, C, D, E, F, G]
Index: []

Example 2: create a dataframe python

import numpy as np
import pandas as pd
vect1=np.zeros(10)
vect2=np.ones(10)
df=pd.DataFrame({'col1':vect1,'col2':vect2})