Note on Python

Interpreted
A program written in a compiled language like C or C++ is converted from the source language i.e. C or C++ into a language that is spoken by your computer (binary code) using a compiler with various flags and options. When you run the program, the linker/loader software copies the program from hard disk to memory and starts running it.
Python, on the other hand, does NOT need compilation to binary. You just run the program directly from the source code. Internally, Python converts the source code into an intermediate form called bytecodes and then translates this into the native language of your computer and then runs it. All this, actually, makes using Python much easier since you don't have to worry about compiling the program, making sure that the proper libraries are linked and loaded, etc. This also makes your Python programs much more portable, since you can just copy your Python program onto another computer and it just works.

String

'What\'s your name?'

or

"What's your name"

Always use raw strings when dealing with regular expressions. Otherwise, a lot of backwhacking may be required.

self:
The reason you need to use self is because Python do methods in a way that makes the instance to which the method belongs to passed automatically, but not received automatically: the first parameter of methods is the instance the method is called on. That makes methods entirely the same as functions, and leaves the actual name to use up to you. self is not special to the code, it's just another object.

pass:
This statement is used when a statement is required syntactically but you do not want any command or code to execute.
The pass statement is a null operation. nothing happens when it executes. The pass is also useful in places where your code will eventually go, but has not been written yet.

JSON (JavaScript object Notation)
A lightweight data-interchange format. It is easy for machines to parse and generate. It is based on a subset of Javascript. JSON is a text format that is completely language independent but uses conventions that are familiar to programers of the C-family languages.

JSON is built on two structures:

• A collection of name/value pairs. In various languages, this is realized as an object, record, struct, dictionary, hash table, keyed list or associative array.
• An ordered list of values. In most languages, the is realized as an array, vector, list, or sequence. 

inspect module: 
get the doc source file of a module

import inspect
inspect.getsourcefile(array)

chr() and ord()
chr() returns a string of one character whose ASCII code is the integer i:

>>> print(chr(97))
a

ord(): Given a string of length 1, return an integer representing the Unicode code point of the character when the argument is a unicode object.

>>> ord('a')
97

leading and trailing underscores:

• single leading underscore (_function): weak "internal use" indicator. e.g., "from M import X" does not import objects whose name starts with an underscore
• single trailing underscore (function_): used by convention to avoid conflicts with Python keyword. e.g., class_='ClassName'
• double leading underscore(__function): when naming a class attribute, invokes name mangling.

name mangling: 

If your class is intended to be subclassed, and you have attributes that you do not want subclasses to use, consider naming them with double leading underscores and no trailing underscores. This invokes Python's name mangling algorithm, where the name of the class is mangled into the attribute name. This helps avoid attribute name collisions should subclasses inadvertently contain attributes with the same name.Python mangles these names with the class name: if class Foo has an attribute named __a , it cannot be accessed by Foo.__a . (An insistent user could still gain access by calling Foo._Foo__a .) Generally, double leading underscores should be used only to avoid name conflicts with attributes in classes designed to be subclassed.

• double leading and trailing underscore: "magic" objects or attributes that live in user - controlled namespaces. e.g., __init__, __file__. Never invent such names, only use them as documented.

__all__

It's a list of public objects of that module, it overrides the default of hiding everything that begins with an underscore.