Question: I have a CSV file with two columns (a and b) of data:

```
a    b
30   3000.01
5    3000.02
1    3001.01
5    3001.02

```

I am using pandas to try and select rows that only have the ".01" values in column "b".
So output should be:

```
a    b
30   3000.01
1    3001.01

```

Basically is there a way to search/select rows in column b with the specified criteria of values ending in ".01"?

Answer: 
Userdata can be updated, but it would require stopping and starting of your EBS backed instance :

<http://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-properties-ec2-instance.html#cfn-ec2-instance-userdata>
```
"Fn::Join": [
        "/n",
        [
            "#!/bin/bash",
            "apt-get update",
            "apt-get -y upgrade",
        ]

```

actually this is the correct way. Don't know whether it is just a typo from your side