#working_with_files
Title: Reading Files

Builtin operator with in python will automatically close the file when you are done processing it.
instead of :
handle = open("test.txt")
can use:
with open("test.txt") as file_handler

#working_with_files
Title:Writing files

#compare
Package with module!
A module is a single importable Python file whereas a package is made up of two or more modules. A package can be imported the same way a module is. Whenever you save a Python script of your own, you have created a module.

#compare
*args and **kwargs
*args - allows your function to get infinite arguments (without keywords)
**kwargs - allows your function to get infinite keyword arguments

*args returns tuple
**kwargs returns dictionary

** — for passing keys and values

Clean Code Principles
✅Code should be elegant and pleasing to read.
✅No duplication should be allowed. Use DRY (Don't Repeat Yourself)
✅Code should be covered with tests.
✅Every function should do one thing and do it well.
✅Codebase should contain only code that is needed.

#compare
Function & Method

A function inside a class changes its name to “method” and method has to have at least one argument (i.e. self)

#compare
all() and any()
all() method demonstrates if List1 has List2 elements

# List1
List1 = ['python' , 'javascript', 'csharp', 'go', 'c', 'c++']

# List2
List2 = ['csharp1' , 'go', 'python']

check = all(item in List1 for item in List2)

any() checks if the list contains any elements of another one:
# List1
List1 = ['python' , 'javascript', 'csharp', 'go', 'c', 'c++']

# List2
List2 = ['swift' , 'php', 'python']

check = any(item in List1 for item in List2)

Time module
time.ctime() - converts a time in seconds since the epoch to a string representing local time ( For Unix systems, the epoch was in 1970).
time.sleep() - suspend execution of your script a given number of seconds like a pause.
time.strftime - create a string that represents the time in a more human readable format.
time.time - returns the time in seconds since the epoch as a floating point number.

#compare
Instance & Attribute

Instance is a Python variable belonging to only one object, accessable in the scope of the object;

Class attribute is a Python variable belonging to a class rather than a particular object.

A "decorator" takes the function below and does something with it

Builtin decorators
@classmethod

✅Declares a class method.
✅The first parameter must be cls, which can be used to access class attributes.
✅The class method can only access the class attributes but not the instance attributes.
✅The class method can be called using ClassName.MethodName() and also using object.

Source_link

Builtin decorators

@staticmethod

✅ Declares a static method in the class.
✅ It cannot have cls or self parameter.
✅ The static method cannot access the class attributes or the instance attributes.
✅ The static method can be called using ClassName.MethodName() and also using object.MethodName().
✅ It can return an object of the class.

Source_link

Builtin decorators

@property

@property decorator turns a class method into a class attribute.
This is useful for combination of values.

Source: Python101(book)

The Python lambda statement is an anonymous or unbound function

It is good for inline functions

SQLAlchemy is usually referred to as an Object Relational Mapper (ORM), although it is much more full featured than any of the other Python ORMs .
SQLAlchemy was created by Michael Bayer

Instead of hiding away SQL and object relational details behind a wall of automation, all processes are fully exposed within a series of composable, transparent tools. The library takes on the job of automating redundant tasks while the developer remains in control of how the database is organized and how SQL is constructed.

The main goal of SQLAlchemy is to change the way you think about databases and SQL!

Source

Updated my course. It now also teaches you how to write your own ORM:

https://mobile.twitter.com/testdrivenio/status/1366746063600762881

#SQL

A JOIN clause is used to combine rows from two or more tables, based on a related column between them.

Collections module

Counter (string sample)

Sort dictionary sample

#Some_JWT_Notes
The access token is usually short-lived (expires in 5 min or so, can be customized though).

The refresh token lives a little bit longer (expires in 24 hours, also customizable). It is comparable to an authentication session. After it expires, you need a full login with username + password again.

Source