Import pytz into AWS lambda function

Question

I'm writing a lambda function that works with datetimes and trying to import pytz so I can have timezone be accounted for when comparing.

import boto3
import pytz
from datetime import timedelta, date, datetime
from boto3.dynamodb.conditions import Key, Attr

causes this to display

{errorMessage=Unable to import module 'lambda_function'}

but when I remove import pytz the function fires (it just doesn't work properly without timezone info)

Pullman

Answer 1

You need to install the pytz package so it's available for your lambda. The way you do this is having pip install it into the directory you are going to zip and upload to AWS (i.e. peered with the file containing your lambda function).

pip install -t path/to/your/lambda pytz

Then when you zip it up and upload it, it will be available.

Editing to add that I created a tool to do a lot of this for you - you can find it here: https://github.com/jimjkelly/lambda-deploy

Presentable

I was hoping to avoid this, but I have a feeling you're probably correct. I'm going to try and find another way to accomplish my end goal, but marking as correct answer for now. much thanks. – Pullman

I've actually been working on a tool to kind of do this automatically (as well as handle pushing it up to AWS for you), but I haven't pushed it up to github just yet. The big pain comes when you are working with libraries with compiled bits. :/ – Presentable

Answer 2

If you don't have access to pytz in your environment, maybe you have access to python-dateutil. In that case you can do:

import datetime
import dateutil.tz

eastern = dateutil.tz.gettz('US/Eastern')
datetime.datetime.now(tz=eastern)

REF. How to get current time in Pacific Timezone when import pytz fails?

Oller

Perfect answer. Happy to use this functionality without having external library. – Eisenach

Answer 3

To follow up on @cheframzi's answer to "Package a pytz zip file in the format python/pytz/..." as a Lambda Layer, here is one way to do that.

mkdir python
pip3 install -t python pytz=='2019.2'
zip -r pytz.zip python
rm -rf python

And then you can use aws lambda publish-layer-version --layer-name <layer_name> --zip-file fileb://./pytz.zip to deploy a new version of the layer.

As long as the library is installed at the python/pytz level of the zip file, AWS Lambda should be able to find it. You can also put it inside python/lib/python3.8/site-packages\pytz though for your specific python runtime version per here: https://docs.aws.amazon.com/lambda/latest/dg/configuration-layers.html

Marseilles

Answer 4

I ran into this issue today. The way I solved is

• Package a pytz zip file in the format python/pytz/... the library file
• Created a Lambda Layer

• In my lambda used the above layer

Millennium

Answer 5

I've spent few hours for this pytz issue. With AWS you can try using the gettz method from 'dateutil.tz'. This way you can get the desired result that you were getting with pytz. In my case I required isoformat time (in utc with (+00:00) timezone).

from datetime import datetime
from dateutil.tz import gettz
datetime.now(gettz('UTC')).isoformat() # same result as datetime.now(pytz.utc).isoformat()

Meditation

Answer 6

You can also add public ARNs as Lambda layers, I used this https://dev.to/vumdao/create-cron-jobs-on-aws-lambda-with-cloudwatch-event-3e07

Isolecithal

Answer 7

import datetime as dt
import dateutil.tz

aesttime = dateutil.tz.gettz('Australia/Brisbane')
print(dt.datetime.now(tz=aesttime).strftime(format="%Y-%m-%d %H:%M:%S"))

Olimpiaolin

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