import pandas as pd
import numpy as np

np.random.seed(0)
df = pd.DataFrame(np.round(np.random.randn(4, 3), 2),
                  columns=list('ABC'))

# Select specific columns
# (first column is 0, second is 1 etc.):
df1 = df.iloc[:, [1, 2]]
print('df1 ='); print(df1); print('')

# Select specific columns AND rows:
df2 = df.iloc[1:3, [1, 2]]
print('df2 ='); print(df2); print('')

# Column A + column  C is stored in new colunm named A+C:
df['A+C'] = df.A + df.C 
print("df['A+C'] ="); print(df); print('')

# Delete specific columns:
df3  = df.drop(columns = ['B', 'C'])
print('df3 ='); print(df3); print('')

# Delete spesific row:
df4  = df.drop(index = 2)
print('df4 ='); print(df4); print('')

arr_from_df4 = df4.to_numpy()
print('arr_from_df4 ='); print(arr_from_df4); print('')