appendix.md

Appendix A

Python Standerd Libery

Once you have python installed in your system you need a set of standard libraries to help build applications. On python these are present in the Lib/ folder of your python installation. These are written in python and act as the building base of applications.

Appendix B

Introduction to PyPy

Setting up PyPy

Download PyCharm :

https://www.jetbrains.com/pycharm/download/#section=linux

Clone pypy:

$git clone https://bitbucket.org/pypy/pypy

Import pypy into PyCharm:

What is PyPy ?

PyPy is a Python interpreter and just-in-time compiler. PyPy focuses on speed, efficiency and compatibility with the original CPython interpreter.[1]

PyPy started out being a Python interpreter written in the Python language itself. Current PyPy versions are translated from RPython to [C code](https://en.wikipedia.org/wiki/C_(programming_language) and compiled. The PyPy JIT compiler is capable of turning Python code into machine codeat run time.

Code Object:

It is defined in the file pypy/interpreter/pycode.py. Let us examine the fields of the class.

self.co_argcount
self.co_nlocals
self.co_stacksize
self.co_flags
self.co_code
self.co_consts_w
self.co_names_w]
self.co_varnames
self.co_freevars
self.co_cellvars
self.co_filename
self.co_name
self.co_firstlineno
self.co_lnotab

# store the first globals object that the code object is run in in
# here. if a frame is run in that globals object, it does not need to
# store it at all

self.w_globals
self.hidden_applevel
self.magic

It is very visibly similar to the PyCodeObject of Cpython.

Function Object:

It is defined in the file pypy/interpreter/function.py. Let us examine the fields of the class.

self.name
self.w_doc
self.code
self.w_func_globals
self.closure
self.defs_w
self.w_func_dict
self.w_module

It is very similar to the function object defined as a C structure in CPython.

Frame Object:

It is defined in the file pypy/interpreter/pyframe.py

frame_finished_execution

last_instr = -1

last_exception = None

f_backref = jit.vref_None

escaped = False # see mark_as_escaped()

debugdata = None

pycode = None # code object executed by that frame

pycode = None # code object executed by that frame

locals_cells_stack_w = None # the list of all locals, cells and the valuestack

valuestackdepth = 0 # number of items on valuestack

lastblock = None

Generator Object:

It is defined in the file pypy/interpreter/generator.py.

self.space
self.frame
self.pycode
Self.running

It is strikingly similar to the generator object of Cpython.

Integer Object:

It is defined in the file pypy/objspace/std/intobject.py on line number 311.

Complex Object:

It is defined in the file pypy/objspace/std/complexobject.py on line number 186.

Float Object:

It is defined in the file pypy/objspace/std/floatobject.py on line number 139.

Dictionary Object:

It is defined in the file pypy/objspace/std/dictmultiobject.py on line number 360.

List Object:

It is defined in the file pypy/objspace/std/listobject.py on line number 168.

Interpreter Loop:

The interpreter loop of pypy is located in the file pypy/interpreter/pyopcode.py on line number 145 which is the function dispatch_bytecode. It is very similar to the PyEvalFrameEx function which is the interpreter loop of Cpython.

Parsing (US/ˈpɑːrsɪŋ/ ; UK/ˈpɑːrzɪŋ/ or syntactic analysis is the process of analysing a string of symbols, either in natural language or in computer languages, conforming to the rules of a formal grammar.

A parser is a software component that takes input data (frequently text) and builds a [data structure] – often some kind of parse tree, abstract syntax tree or other hierarchical structure – giving a structural representation of the input, checking for correct syntax in the process. The parsing may be preceded or followed by other steps, or these may be combined into a single step.

AST

In computer science, an abstract syntax tree (AST), or just syntax tree, is a tree representation of the abstract syntactic structure of source code written in a programming language. Each node of the tree denotes a construct occurring in the source code. The syntax is "abstract" in not representing every detail appearing in the real syntax.