Python AWS Boto3: How to read files from S3 bucket?

Question

Using Boto3, the python script downloads files from an S3 bucket to read them and write the contents of the downloaded files to a file called `blank_file.txt`. My question is, how would it work the same way once the script gets on an AWS Lambda function?

Accepted Answer

Lambda provides 512 MB of `/tmp` space. You can use that mount point to store the downloaded S3 files or to create new ones.

```
s3client.download_file(bucket_name, obj.key, '/tmp/'+filename)
...
blank_file = open('/tmp/blank_file.txt', 'w')
```

The working directory used by Lambda is `/var/task` and it is a read-only filesystem. You will not be able to create files in it.

Python AWS Boto3: How to read files from S3 bucket?

Solution

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