import pandas as pd
import numpy as np
data = {'A': [1,2,3,4,np.nan,5,np.nan,np.nan,6,7,8,np.nan],
'B': [7,8,np.nan,9,np.nan,np.nan,10,12,13,np.nan,11,12],
'C': [100,200,300,np.nan,5,np.nan,np.nan,0,8,np.nan,np.nan,99]
}
df = pd.DataFrame(data,columns=['A', 'B', 'C'])
print(df)
'''
run:
A B C
0 1.0 7.0 100.0
1 2.0 8.0 200.0
2 3.0 NaN 300.0
3 4.0 9.0 NaN
4 NaN NaN 5.0
5 5.0 NaN NaN
6 NaN 10.0 NaN
7 NaN 12.0 0.0
8 6.0 13.0 8.0
9 7.0 NaN NaN
10 8.0 11.0 NaN
11 NaN 12.0 99.0
'''