Question: ```
 with open(filename,"r") as f:
       reader = csv.reader(f,delimiter = ",")
       data = list(reader)
       rownum = len(data)
 with open(filename2,"r") as f:
       reader2 = csv.reader2(f,delimiter = ",")
       data2 = list(reader2)
       rownum2 = len(data)

 if rownum > rownum2:
       delete(rownum until rownum = rownum2 at end)

```

Answer: 
An easy google search would probably gotten you the answer, but if you just want the binary representation of numbers from 0 to 32.

```
public static void Main()
    {
        for (int i = 0; i < 32; i++)
        Console.WriteLine(Convert.ToString(i, 2).PadLeft(5, '0'));
    }

```
```
for (int i= 0; i < 32; i++)
{
  // i is a packed combination
  // j-th bit is (i >> j) & 1
}

```