[python] how to calculate percentage in python

This is my program

print" Welcome to NLC Boys Hr. Sec. School "
a=input("\nEnter the Tamil marks :")
b=input("\nEnter the English marks :")
c=input("\nEnter the Maths marks :")
d=input("\nEnter the Science marks :")
e=input("\nEnter the Social science marks :")
tota=a+b+c+d+e
print"Total is: ", tota
per=float(tota)*(100/500)
print "Percentage is: ",per

Result

Welcome to NLC Boys Hr. Sec. School 

Enter the Tamil marks :78

Enter the English marks :98

Enter the Maths marks :56

Enter the Science marks :65

Enter the Social science marks :78 Total is:  375 Percentage is:  0.0

However, the percentage result is 0. How do I calculate the percentage correctly in Python?

I know I am late, but if you want to know the easiest way, you could do a code like this:

number = 100
right_questions = 1
control = 100
c = control / number
cc = right_questions * c
print float(cc)

You can change up the number score, and right_questions. It will tell you the percent.

This is because (100/500) is an integer expression yielding 0.

Try

per = 100.0 * tota / 500

there's no need for the float() call, since using a floating-point literal (100.0) will make the entire expression floating-point anyway.

marks = raw_input('Enter your Obtain marks:')
outof = raw_input('Enter Out of marks:')
marks = int(marks)
outof = int(outof)
per = marks*100/outof
print 'Your Percentage is:'+str(per)

Note : raw_input() function is used to take input from console and its return string formatted value. So we need to convert into integer otherwise it give error of conversion.

def percentage_match(mainvalue,comparevalue):
    if mainvalue >= comparevalue:
        matched_less = mainvalue - comparevalue
        no_percentage_matched = 100 - matched_less*100.0/mainvalue
        no_percentage_matched = str(no_percentage_matched) + ' %'
        return no_percentage_matched 
    else:
        print('please checkout your value')

print percentage_match(100,10)
Ans = 10.0 %

Percent calculation that worked for me:

(new_num - old_num) / old_num * 100.0

You're performing an integer division. Append a .0 to the number literals:

per=float(tota)*(100.0/500.0)

In Python 2.7 the division 100/500==0.

As pointed out by @unwind, the float() call is superfluous since a multiplication/division by a float returns a float:

per= tota*100.0 / 500