Question: ```
import os

i = 1

PATH = "C:\\Capture "+ str(i)

isFile = os.path.exists(PATH)

while isFile == 0:

  i = i + 1

```

How can I make **'i'**, inside the while loop, update the value of **'str(i)'**?

Answer: 
`[abc]` means the character must be `a` or `b` or `c`.

To match a character that is `a` and `b` and `c`, you can use the `(?[ ... ])`.[1]

```perl
(?[ [a] & [b] & [c] ])

```

But of course, you don't want AND. You want

```
(?: a.*b.*c
|   a.*c.*b
|   b.*a.*c
|   b.*c.*a
|   c.*a.*b
|   c.*b.*a
)

```

So `/a/ && /b/ && /c/` is *quite* an elegant solution.

---

1. It's an experimental feature, but one I predict will be accepted without change.
If you want `a` and `b` and `c` in any order, you do:

```
$matches = ($word =~ /a/ && $word =~ /b/ && $word =~ /c/);

```