Other techs Linux How to rename multiple files at once
I want to rename multiple files in the same directory at once with index. How can I do it on Linux? Let's combine use for-loop and ls command. Then, rename it in the loop.
Other techs 
Golang Golang How to convert string to float, int
Do you want a cheat sheet to know how to convert value to another data type? This article covers what you want.
Python Python Use lambda to create a function for simple logic
Using lambda is a good choice if a function requires a callback parameter and the logic in the callback is quite simple. Let's learn how to use it if you don't know it.
Python Python 4 ways to remove duplicates from an object list
Do you need to remove duplicates from a list? This post covers not only a literal list but also an object list. If it's an object list, it's harder to remove duplicates than the literal version. Let's check how to implement it!
Python Spread operator in Python? How to unpack list/dict
How can we write if we want to unpack a list in Python? Is there something like spread operator used in JavaScript? Yes. Use an asterisk to unpack the list. Use double asterisk for dict type. Let's look at the examples.
Python Python How to filter object list
Why doesn't Python provide a method to filter a list? It provides filter class instead. You can use it to filter a list/dict. You can also use basic for-loop to do the same thing. Let's learn how to filter a list in this post!
Python Python How to create multiple Threads for async
To make multiple tasks asynchronously, it's necessary to know how to create threads in Python. This post shows how to do it.
Golang Golang Improper package structure exports unneeded members
Do you want to write unit tests for methods but don't want to expose them to outside of the package? Then, move the methods to internal package. The functions defined in internal package are not exposed. Let's learn how to use it.
Python Python Using Literal type to restrict the parameter
How can we restrict parameter values in Python? Use Literal. Enum can also be used for the same purpose but it can break the existing code. Let's learn how to use Literal together.
Golang Golang How to mock an object by yourself for unit testing
It might be too big to introduce a mock framework. It's better to create a mock object by ourselves in this case.