Why am I getting "datetime.datetime" error while using lambda? - amazon-web-services

Question

I am currently using AWS Lambda to write this script:
import boto3
import json
s3 = boto3.client("s3")
def lambda_handler(event, context):
bucket = "www.onlinecodecompiler.com"
key = "aws_cli_bucket.txt"
try:
data = s3.get_object(Bucket=bucket, Key=key)
json_data = data["Body"].read()
return{
"response_code ": 200,
"data": data
}
except Exception as e:
print(e)
raise(e)
The txt file "aws_cli_bucket.txt" has the following sentence in it, "list all object in a bucket aws s3 ls s3:// bucket name". Its just a random text I had because I was just testing to see if lambda could read a text file from my S3 bucket but why am I getting an error stating
datetime.datetime(2021, 3, 22, 19, 50, 48, tzinfo=tzutc()) is not JSON serializable
I searched online and most people were getting this error because their code had something to do with date and time but mine does not.
Any help would be greatly appreciated.

Answer 1

The error stems from the response which you are getting from the s3.get_object which contains 3 datetime objects
{
'Body': StreamingBody(),
'DeleteMarker': True|False,
'AcceptRanges': 'string',
'Expiration': 'string',
'Restore': 'string',
'LastModified': datetime(2015, 1, 1),
...
'Expires': datetime(2015, 1, 1),
...
'ObjectLockRetainUntilDate': datetime(2015, 1, 1),
}
s3.get_object
Before returning the you also have to remove the Body key as well, which contains StreamingBody() otherwise it will error for that as well.
"errorMessage": "Unable to marshal response: <botocore.response.StreamingBody object at 0x7fa2370625d0> is not JSON serializable",
Depending on your needs you can simply delete those fields as do as you want.
import boto3
s3 = boto3.client('s3')
def lambda_handler(event, context):
try:
data = s3.get_object(Bucket='enrichedobjects1', Key='x.py')
json_data = data["Body"].read()
del data['Body']
del data['LastModified']
return{
"response_code ": 200,
"data": data
}
except Exception as e:
print(e)
raise(e)
The above code produces the following response
{
"response_code ": 200,
"data": {
"ResponseMetadata": {
"RequestId": "980JCEDBG0AWZH",
"HostId": "Oscwxx/5str0NFoWbnP/f5SAS4euhiJPQUXx7uOs205fowd7ICNtU=",
"HTTPStatusCode": 200,
"HTTPHeaders": {
"x-amz-id-2": "Oscwxx/5Xk3uv7LuFUDx7uOs205fowd7ICNtU=",
"x-amz-request-id": "980JC0KEDBWZH",
"date": "Mon, 22 Mar 2021 20:43:56 GMT",
"last-modified": "Sat, 20 Mar 2021 17:35:25 GMT",
"etag": "\"d41d8cd98f00b20498ecf8427e\"",
"accept-ranges": "bytes",
"content-type": "text/x-python",
"content-length": "0",
"server": "AmazonS3"
},
"RetryAttempts": 1
},
"AcceptRanges": "bytes",
"ContentLength": 0,
"ETag": "\"d41d8cd98f00b00998ecf8427e\"",
"ContentType": "text/x-python",
"Metadata": {}
}
}