Matrix operations - python

def display_menu():
""" prints a menu of options
"""
print()
print('(0) enter a new matrix')
print('(1) negate the matrix')
print('(2) multiply a row by a constant')
print('(3) add one row to another')
print('(4) add a multiple of one row to another')
print('(5) transpose the matrix')
print('(6) quit')
print()

def print_matrix(matrix):
""" prints the specified matrix in rectangular form.
input: matrix is a 2-d list numbers
"""
## you will revise this function.
print(matrix)

def get_matrix():
""" gets a new matrix from the user and returns it
"""
matrix = eval(input('enter a new 2-d list of numbers: '))
return matrix