Answers for "how make sure that all the column is numbers in python"

get column number in dataframe pandas

# PANDAS: get column number from colomn name
dataframe.columns.get_loc("<col_name>")

How many columns have null values present in them? in pandas

import pandas as pd
df = pd.DataFrame({'a':[1,2,np.nan], 'b':[np.nan,1,np.nan],'c':[np.nan,2,np.nan], 'd':[np.nan,np.nan,np.nan]})
print(pd.isnull(df).sum())