Hey there! I've already written the codes, and I need help with the RED MARKED place.

I don't know how to deal with the def main() part and argv with the sys.exit()

Please help me to fix the code and make it fit the description.

Thank you!

******Below my codes with some errors******

# Header comment section (typical assignment info)

import sys

#The matrices A and B must be declared as empty lists: A = [] and B = []

A = []

B = []

# read_matrices is a function that takes two parameters A and B

# it reads the file and store the matrix values in it

# it return A and B m,n,p values

print("Program #3, csscxxx, xxx")

# This function reads m, n, and p from the datafile.

# Then matrices A and B are filled from the datafile.

# Matrix C is then allocated size m x p.

# The values for m, n, and p are local values filled in by this function

# PARAMETERS in order are:

# list matrix A

# list matrix B

# RETURN matrix C

#

def read_matrices(A,B):

filename = sys.argv[-1]

file1 = open(filename, 'r')

Lines = file1.readlines()

m = int(Lines[0])

n = int(Lines[1])

p = int(Lines[2])

for i in range(3,m+3):

# add the values to A

A.append(list(map(int,(Lines[i].split()))))

for i in range(m+3,n+m+3):

# get data to B

B.append(list(map(int,(Lines[i].split()))))

return A,B,m,n,p

# The two matrices A and B are multiplied, and matrix C contains the

# result.

# PARAMETERS in order are:

# list Matrix A

# list Matrix B

# list Matrix C (all zeros at this point)

#

def mult_matrices(A,B,C):

for i in range(m):

for j in range(p):

C[i][j] = 0

# iterate + compute the sum

for k in range(n):

C[i][j]+=A[i][k]*B[k][j]

return C

# This function prints a matrix. Rows and columns should be preserved.

# PARAMETERS in order are:

# list The matrix to print

#

def print_matrix(arr):

for i in range(len(arr)):

for j in range(len(arr[i])):

print("{:>5}".format(arr[i][j]),end="")

print()

# This function begins execution of program.

# Verify data input filename provided on command line: len(sys.argv)

# If error, output message for user: Usage: p3.py dataFileName'

# and quit, using sys.exit()

#

# Declare A, B, call read_matrices to initialize A, B, and store

# return value as C

#

# Print A and B contents

#

# Call mult_matrices

#

# Print result contents

#

# Main function

if __name__=="__main__": filename = sys.argv[-1] """ In place of If/else codition we can also use try/except block in python to raise an expected Error. """

if filename==len(sys.argv): continue else: print("Error: - Usages: p3.py DataFileName") sys.exit() ### In place of sys.exit() we can also terminate the program using break statement. A,B,m,n,p = read_matrices(A,B) C = [[0]*p for i in range(m)] mult_matrices(A,B,C) print("Matrix A contents: ") print_matrix(A) print("Matrix B contents: ") print_matrix(B) print("Matrix A * B is: ") print_matrix(C)

The Program: For this assignment, you will multiply two matrices and print the result. If A is an mx n matrix, and B is an n xp matrix, then the product matrix C, which is A x B, is defined to be the m xp matrix whose entry in the ith row and the jih column is the sum of the products of corresponding entries of the ith row of A and the jih column of B. A standard algorithm is: for (int i=0; i