multipart/form-data support in AWS Chalice

Hello,

How would I parse the raw_body to get the filename and file content from "multipart/form-data" content-type request to PUT to S3?

When I tried the same with Flask, it has a request.files object property to extract the file content from the body:

```python
@app.route('/upload', methods=['POST'])
def upload():
try:
print request.__dict__
session = Session(aws_access_key_id='xxx',
aws_secret_access_key='xxxx',
region_name='xxx')
s3 = session.resource('s3')
s3.Bucket('my-bucket').put_object(Key='my-folder/mydata_file.pdf', Body=**request.files**['myfile'])
except Exception as e:
print str(e)
```

Does AWS Chalice supports multipart/form-data to get the file object like Flask (request.files)?

Or Is there another way to parse the raw_body?

Regards,
Pawan

Start by reviewing AWS Chalice's handling of raw_body for API Gateway requests and the multipart/form-data behavior described in the issue. Compare the requested file extraction with Flask's request.files and S3 upload use case; done should mean a supported or clearly documented way to obtain the filename and file content.

Written by the indexing model from the issue text.