I am trying to find all `p` tags with the class `column`.

```
<p class="column">This is a column</p>
<p class="column">More columns heh</p>

```

I tried doing:

```
soup.find_all(class_='column')

```

which returned `[]`

Then I tried:

```
soup.find_all(attrs={'class': 'column'})

```

and got the right results.

Shouldn't these two statements be identical? What's the difference?