Page Replacement simulation in Python

page_replacement

a = []

#Function to accept reference string and frame size.
def accept():
    global a,n,m
    n = input("\n Enter the size of reference string : ")
    for i in range(n):
        a.append(input(" Enter [%2d] : " % (i+1)))
    m = input("\n Enter page frame size : ")

#First In First Out Page Replacement Algorithm
def __fifo():
    global a,n,m
    f = -1
    page_faults = 0
    page = []
    for i in range(m):
        page.append(-1)

    for i in range(n):
        flag = 0
        for j in range(m):
            if(page[j] == a[i]):
                flag = 1
                break

        if flag == 0:
            f=(f+1)%m
            page[f] = a[i]
            page_faults+=1
            print "\n%d ->" % (a[i]),
            for j in range(m):
                if page[j] != -1:
                    print page[j],
                else:
                    print "-",
        else:
            print "\n%d -> No Page Fault" % (a[i]),
            
    print "\n Total page faults : %d." % (page_faults)

#Least Recently Used Page Replacement Algorithm
def __lru():
    global a,n,m
    x = 0
    page_faults = 0
    page = []
    for i in range(m):
        page.append(-1)

    for i in range(n):
        flag = 0
        for j in range(m):
            if(page[j] == a[i]):
                flag = 1
                break
            
        if flag == 0:
            if page[x] != -1:
                min = 999
                for k in range(m):
                    flag = 0
                    j =  i
                    while j>=0:
                        j-=1
                        if(page[k] == a[j]):
                            flag = 1
                            break
                    if (flag == 1 and min > j):
                        min = j
                        x = k

            page[x] = a[i]
            x=(x+1)%m
            page_faults+=1
            print "\n%d ->" % (a[i]),
            for j in range(m):
                if page[j] != -1:
                    print page[j],
                else:
                    print "-",
        else:
            print "\n%d -> No Page Fault" % (a[i]),
            
    print "\n Total page faults : %d." % (page_faults)

#Optimal Page Replacement Algorithm
def __optimal():
    global a,n,m
    x = 0
    page_faults = 0
    page = []
    for i in range(m):
        page.append(-1)

    for i in range(n):
        flag = 0
        for j in range(m):
            if(page[j] == a[i]):
                flag = 1
                break
            
        if flag == 0:
            if page[x] != -1:
                max = -1
                for k in range(m):
                    flag = 0
                    j =  i
                    while j<n:
                        j+=1
                        if(page[k] == a[j]):
                            flag = 1
                            break
                    if (flag == 1 and min < j):
                        max = j
                        x = k

            page[x] = a[i]
            x=(x+1)%m
            page_faults+=1
            print "\n%d ->" % (a[i]),
            for j in range(m):
                if page[j] != -1:
                    print page[j],
                else:
                    print "-",
        else:
            print "\n%d -> No Page Fault" % (a[i]),
            
    print "\n Total page faults : %d." % (page_faults)

    

#Displaying the menu and calling the functions.    
while True:
    print "\n SIMULATION OF PAGE REPLACEMENT ALGORITHM"
    print " Menu:"
    print " 0. Accept."
    print " 1. FIFO."
    print " 2. LRU."
    print " 3. Optimal."
    print " 4. Exit."
    ch = input(" Select : ")

    if ch == 0:
        accept()
    if ch == 1:
        __fifo()
    if ch == 2:
        __lru()
    if ch == 3:
        __optimal()
    if ch == 4:
        break

Hi friend!!
In my simulation I must enter the following command-line parameters:
• Maximum number of frames
• Minimum number of frames per process
• Number of processes
• Process Size (remember that the number of frames to allocate is --- ai = (Si/sum Si)x m --- where Si=process size in pages and m=number of frames avaible
• The length of the reference sequence

Could you tell me how to change the accept function?