Welcome to the Treehouse Community

The Treehouse Community is a meeting place for developers, designers, and programmers of all backgrounds and skill levels to get support. Collaborate here on code errors or bugs that you need feedback on, or asking for an extra set of eyes on your latest project. Join thousands of Treehouse students and alumni in the community today. (Note: Only Treehouse students can comment or ask questions, but non-students are welcome to browse our conversations.)

Looking to learn something new?

Treehouse offers a seven day free trial for new students. Get access to thousands of hours of content and a supportive community. Start your free trial today.

negate.py help

I'm not sure I understand what order to put things in. I tried a bunch of combinations using the plus sign and a negation set, but I keep getting the original string or an empty string. Or, sometimes I get numbers broken between commas, and for some reason the number 7 is always still there. Any help is appreciated.

negate.py
```import re

string = '1234567890'
good_numbers = re.findall(r'\d+[^567]', string)
```

You're pretty close - there's no need for the \d, which recognizes a digit generally https://stackoverflow.com/a/6479605/3182843

The [^567] reads NOT match a 5 or 6 or 7

```>>> import re
>>> string = '1234567890'
>>> # Create a variable named good_numbers that is an re.findall() where the pattern matches anything in string except the numbers 5, 6, and 7.
...
>>> re.findall(r'[^567]', string)
['1', '2', '3', '4', '8', '9', '0']
```

had you something like this and wanted to only return digits

```>>> data = "jeffrey34"
>>> re.findall(r'\d+', data)
['34']
>>>
```

Thanks for the reply. My next question is why does something like r'[^567]+, string

return ['1234', '890]

I though it would make it into a continuous string, like ['1234890']

The + operator is a repetition character. So if you're saying to match all blocks of non 5s, 6s or 7s, it finds 2 of them in your original string. To be honest, that's fairly obscure. Usually, at least in my experience, when you write regexp, you inevitably have to fool around to get it correct, especially on non trivial problems. You also may not fully understand what happened, but you can verify that it worked :)

```>>> re.findall( r'[^567]', string)
['1', '2', '3', '4', '8', '9', '0']
>>> re.findall( r'[^567]+', string)
['1234', '890']
```