# Import the NumPy library
import numpy as np

# create a 2D array
arr = np.array([[1, 2, 0], [3, 0, 5], [0, 6, 7]]) 

# check if any columns are all zero
has_null_columns = np.any(np.sum(arr, axis=0) == 0) 

# printing results (T/F)
print(has_null_columns)