Error in python code

Question

I am new at Python. Here is my code which scans number of test cases tc as input and then two integers r and c and calculating my result.

Question: How to remove the error?

#!bin/bash/python
tc=int(input());
while tc:
    r,c=raw_input().split()
    if r%2==0:
        r=r/2
    else:
        r=r/2+1
    print(r*c)
    tc=tc-1

4       //input tc
10 10   //input r=10 c=10

Error displayed at the screen:

Traceback (most recent call last):
File "spoj_solders.py", line 5, in <module>
  if r%2==0:
TypeError: not all arguments converted during string formatting

What is this string formatting?

Platform: Ubuntu 10.04

snim2 · Accepted Answer · 2012-01-10 23:34:33Z

2

The line r,c=raw_input().split() takes text from the user (raw_input()), returns it as a str type and splits that into two strings (separated by a space) and stores those in the variables r and c. So, r is a str, you can't say if r%2==0: without casting r to an int like this:

r,c=raw_input().split()
if int(r)%2==0:
    r=int(r)/2
else:
    r=int(r)/2+1
print(r*c)
tc=tc-1

answered Jan 10, 2012 at 23:34

snim2

4,0891 gold badge32 silver badges46 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

Anil Arya Over a year ago

I want the answer 50 for r=10 & c=10 ,but is giving 1010101010,tc=4

Mark Streatfield · Accepted Answer · 2012-01-10 23:35:04Z

2

The result of the split() call is a list of strings, therefore the r and c variables are also strings.

So, when it comes to using the % operator on r Python is performaning string formatting and not the modulus operation you expect.

You need to cast r into a variable of the correct type first (using float(r) for example).

answered Jan 10, 2012 at 23:35

Mark Streatfield

3,2191 gold badge25 silver badges19 bronze badges

3 Comments

John Lyon Over a year ago

You should use math.fmod() if you are using a float. If the input is cast to an int instead of a float, using r % 2 is fine. You could always check whether the user has entered a decimal point to determine which method to use.

John Machin Over a year ago

@jozzas: Try int("1e-5") sometime.

John Lyon Over a year ago

@John if you expect users will provide input in scientific notation, your program should account for that too :)

Collectives™ on Stack Overflow

Error in python code

2 Answers 2

1 Comment

3 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

1 Comment

3 Comments

Your Answer

Sign up or log in

Post as a guest

Related