Not understanding part of this code

I’m studying how to encrypt an image file using RSA algo and i find this code on the internet, the code is running well but i am not understanding it completely. I know how the algorithm works and how to generate keys but but i am not getting the code.Please help me to understand the code. Here is the code:

print(jpgfile.bits, jpgfile.size, jpgfile.format) row,col = jpgfile.size pixels = jpgfile.load() 

From Here

row1 = 1000003 phi = [0 for x1 in range(row1)] occ = [0 for x1 in range(row1)] primes = []  phi[1] = 1 #phi[2] = 1 #print (phi) for i in range(2,1000001):     #print (i)     if(phi[i] == 0):         phi[i] = i-1         #print (i)         primes.append(i)         #j = 2*i         for j in range (2*i,1000001,i):         #print("j ",j)         #print(j)         if(occ[j] == 0):             #print ("inside if2")             occ[j] = 1             phi[j] = j             #print (phi[j])             #print ((i-1)//i)         phi[j] = (phi[j]*(i-1))//i         #print(phi[j])         #j = j + i #print (primes) p = primes[random.randrange(1,167)] q = primes[random.randrange(1,167)] print(p," ", q) n = p*q mod = n phin1 = phi[n] phin2 = phi[phin1] e = primes[random.randrange(1,9000)] mod1 = phin1 def power1(x,y,m):     ans=1     while(y>0):         if(y%2==1):             ans=(ans*x)%m         y=y//2         x=(x*x)%m     return ans d = power1(e,phin2-1,mod1) enc = [[0 for x in range(row)] for y in range(col)] dec = [[0 for x in range(row)] for y in range(col)] for i in range(col):     for j in range(row):         r,g,b = pixels[j,i]         r1 = power1(r+10,e,mod)         g1 = power1(g+10,e,mod)         b1 = power1(b+10,e,mod)         enc[i][j] = [r1,g1,b1] print(pixels[row-1,col-1]) img = numpy.array(enc,dtype = numpy.uint8) img1 = Image.fromarray(img,"RGB") #pixels2 = img1.load() for i in range(col):     for j in range(row):         r,g,b = enc[i][j]         r1 = power1(r,d,mod)-10         g1 = power1(g,d,mod)-10         b1 = power1(b,d,mod)-10         dec[i][j] = [r1,g1,b1] img2 = numpy.array(dec,dtype = numpy.uint8) img3 = Image.fromarray(img2,"RGB")