You can become a serverless blackbelt. Enrol to my 4-week online workshop Production-Ready Serverless and gain hands-on experience building something from scratch using serverless technologies. At the end of the workshop, you should have a broader view of the challenges you will face as your serverless architecture matures and expands. You should also have a firm grasp on when serverless is a good fit for your system as well as common pitfalls you need to avoid. Sign up now and get 15% discount with the code yanprs15!
A while back I decided to try and learn Python for the hell of it as it seems like an interesting language and has some of the most concise and user-friendly syntax. Having spent some time going through a number of different learning sources and materials (like the official site python.org which has a very helpful tutorial section) I have put together a set of notes I made as I was learning and hopefully they can be useful to you as a quick list of how-to code snippets.
All the code snapshots I’m showing here are taken from the IDLE Python shell.
To create a new list:
Lists are NOT immutable:
Use the in keyword to check whether an element is in the specified list:
The min and max functions:
The list function – you can use the list() function to convert a tuple to a list:
Element values of a tuple cannot be changed and tuple elements are put between parenthesis instead of square bracket:
Deleting an item from list:
or you can use the remove() function:
Replace portion of list with slicing:
Insert a list into another list with slicing:
Delete a portion of list with slicing:
Appending to a list by using simple concatenation:
or use append or extend, the difference being append adds a single element to the list where as extend works like the concatenation above.
now compare this to extend:
You can also use a list as a queue (FIFO) using the collections.deque function:
Sorting a list:
you can do the same to a string too using the sorted function:
To construct an empty tuple:
To construct a tuple with a single item:
You can unpack a tuple or list (like the pattern matching in F#):
There must be the same number of elements on the left as the tuple on the right:
Use the range() function to generate a range of integers:
Use the filter() function to filter a list:
Use the map() function to project a sequence’s items to something else:
you can also use it like the zip() method in F# by passing in multiple sequences:
if the lists are not of equal length, None is used to fill in the gap:
Use the reduce() function to return a single value from a list of element, e.g. to sum the numbers 1-4:
you can also pass in a third argument to indicate the starting value of the accumulator:
You can remove an item from a list using its index with the del statement:
note that del statement doesn’t return any values.
You can also use it to delete the entire list or part of the list:
or to delete the variable itself:
List comprehensions (similar to those in F#):
If the result is a tuple, then it must be parenthesized:
You can add additional filters:
Or you can have a loop inside another loop:
Nested List Comprehensions, e.g. to turn the columns of a matrix into rows:
remember, read nested comprehensions from right to left!
Nested comprehensions is a powerful tool but adds complexity, where possible, use built-in functions. E.g. the above can be done using zip():
When looping through a sequence, the position index and corresponding value can be retrieved at the same time using the enumerate() function:
You can also use zip() function to loop over two or more sequences at the same time:
Hi, I’m Yan. I’m an AWS Serverless Hero and I help companies go faster for less by adopting serverless technologies successfully.
Are you struggling with serverless or need guidance on best practices? Do you want someone to review your architecture and help you avoid costly mistakes down the line? Whatever the case, I’m here to help.
Skill up your serverless game with this hands-on workshop.
My 4-week Production-Ready Serverless online workshop is back!
This course takes you through building a production-ready serverless web application from testing, deployment, security, all the way through to observability. The motivation for this course is to give you hands-on experience building something with serverless technologies while giving you a broader view of the challenges you will face as the architecture matures and expands.
We will start at the basics and give you a firm introduction to Lambda and all the relevant concepts and service features (including the latest announcements in 2020). And then gradually ramping up and cover a wide array of topics such as API security, testing strategies, CI/CD, secret management, and operational best practices for monitoring and troubleshooting.
If you enrol now you can also get 15% OFF with the promo code “yanprs15”.
Check out my new podcast Real-World Serverless where I talk with engineers who are building amazing things with serverless technologies and discuss the real-world use cases and challenges they face. If you’re interested in what people are actually doing with serverless and what it’s really like to be working with serverless day-to-day, then this is the podcast for you.
Check out my new course, Learn you some Lambda best practice for great good! In this course, you will learn best practices for working with AWS Lambda in terms of performance, cost, security, scalability, resilience and observability. We will also cover latest features from re:Invent 2019 such as Provisioned Concurrency and Lambda Destinations. Enrol now and start learning!
Check out my video course, Complete Guide to AWS Step Functions. In this course, we’ll cover everything you need to know to use AWS Step Functions service effectively. There is something for everyone from beginners to more advanced users looking for design patterns and best practices. Enrol now and start learning!
Here is a complete list of all my posts on serverless and AWS Lambda. In the meantime, here are a few of my most popular blog posts.
- All you need to know about caching for serverless applications
- Lambda optimization tip – enable HTTP keep-alive
- You are wrong about serverless and vendor lock-in
- You are thinking about serverless costs all wrong
- Just how expensive is the full AWS SDK?
- Check-list for going live with API Gateway and Lambda
- How to choose the right API Gateway auth method
- CloudFormation protip: use !Sub instead of !Join
- AWS Lambda – should you have few monolithic functions or many single-purposed functions?
- Guys, we’re doing pagination wrong
- Top 10 Serverless framework best practices
- How to break the “senior engineer” career ceiling
- My advice to junior developers