Merge pull request 'naming-convention' (#1) from naming-convention into main

Reviewed-on: https://gitea.com/Lerking/python-crash-course/pulls/1

basics/mutable_and_immutable_objects.py

@@ -0,0 +1,59 @@
+"""
+Mutable and immutable objects
+"""
+
+# A mutable object is an object which can be modified in place.
+# In python, everything is an object(class). So creating any variable
+# will create a class instance of that object type, with a specific set of methods,
+# which can operate on the object. It will also contain the content.
+#
+# A mutable object is an object which stays the same object, no matter what legal operation you do on it.
+# There are basically 3 types of mutable objects in python.
+# Lists, dictionaries and sets.
+list()
+dict()
+set()
+
+# What makes these objects mutable, is the fact that you can alter the content without
+# altering the object itself. i.e. you can append items to a list or remove items from a list.
+# The same mechanics are true for dictionaries and sets.
+
+# Immutable objects are objects that can't be changed.
+# These are some of the types which are immutable.
+str()
+int()
+float()
+
+# What characterisses an immutable object, is that the object itself holds the content.
+# In other words, 1 value = 1 object. Take the following example.
+A: int = 5
+B: int = 5
+
+# Here, we have created 2 objects 'A' and 'B', both with the integer value '5'.
+# What happens in python is that when creating such objects, it will start by searching
+# already created objects to see if an object with this specific value has already been
+# created. If python finds that an object of this particular type and value exists, it
+# will return a pointer to this object.
+# That means that in our example, both 'A' and 'B' are the same object. We can prove that
+# with the following. Using id() on the variable(class object) will show the internal
+# python id of that object.
+print(id(A))
+print(id(B))
+
+# So we can see that these objects both points to the same internal object, meaning that
+# only 1 int(5) object exists, but we can have multiple varables pointing to it.
+# This is exactly what immutable objects are. There can be only 1 of each.
+# Now explore the following.
+A: int = 5
+B: int = 5
+print(id(A))
+print(id(B))
+B += 1 # add 1 to variable 'B'
+print(id(A))
+print(id(B))
+
+# What happens here?
+# Now variable 'A' still points to the int(5) class object. But a new int(6) clas object
+# have been created and variable 'B' now points to this object.
+# The same is the case with string objects. Each string object can only contain the string
+# value, it was created with.

basics/naming_convention.py

@@ -0,0 +1,87 @@
+"""
+Basic naming conventions in python.
+We will be covering the following.
+Variables, functions, classes, methods
+"""
+
+"""
+Variables - Predefined
+"""
+# Do's
+# Use UPPERCASE in combination with snakecase
+HOME_FOLDER = "/home/me"
+
+# Dont's
+# Do not use lowercase for variable names.
+home_folder = "/home/me"
+
+# When using UPPERCASE letter for variables, it becomes extremely easy to
+# identify variable names in your code, at a single glance.
+# If you use lowercase letter for variable names, they will be harder to see
+# in your code, as they would be easily misidentified as function names.
+
+"""
+Functions
+"""
+# Do's
+# Use lowercase in combination with snakecase for functions.
+# Use describing names for functions, which makes it easier to identify what
+# the given function is used for.
+# Always use types in function headers.
+# Always show th return type in function headers.
+# Using types in the function header makes it a lot easier for others to
+# see how your function is supposed to work. A further effect, is that linters
+# will show warnings correctly.
+def save_file(filename: str) -> None:
+    with open(filename, "w") as F:
+        F.write()
+
+# Dont's
+# Dont use CamelCase or UPPERCASE in function names.
+# Dont leave out types in your function headers.
+def SaveFile(filename):
+    with open(filename, "w") as F:
+        F.write()
+        
+def SAVEFILE(filename):
+    with open(filename, "w") as F:
+        F.write()
+
+# Using CamelCase for function names, could confuse them with class names.
+# Using UPPERCASE letters for function names, could confuse them with variable names.
+
+"""
+Classes
+"""
+# Do's
+# Use CamelCase for class names
+# Functions defined inside a class are called methods. Differentiating between function
+# and method makes it easier for people to know what you're refering to.
+# A method wil ALWAYS take 'self' as it's first parameter. 'self' is the actual class reference
+# this method is operating on.
+class MyClass:
+    def __init__(self, folder: str = ""):
+        self.folder = folder
+        
+    def save_file(self, filename: str) -> None:
+        with open(self.folder + filename, "w") as F:
+            F.write()
+
+# Dont's
+# Don't user lowercase, uppercase or snakecase in class names.
+# Be careful to give your classes meaningful names. Preferably describing what the class is used for.
+
+# You can create several instances of the same class. Which is where 'self' comes into play.
+myclass = MyClass()
+myclass_1 = MyClass(folder = "/home/me/")
+myclass.save_file("test.txt")
+myclass_1.save_file("my_file.txt")
+
+"""
+Methods
+"""
+# The same rules applies to methods as functions as they are in essense the same.
+# The difference between functions and methods, lies in where the were defined.
+# If a function is defined inside a class, it becomes a method. That means a method
+# of functionality for it's defining class.
+# Any other function definitions are just functions.