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In this tutorial we're going to build a set of parser combinators.

What is a parser combinator?

We'll answer the above question in 2 steps

1. what is a parser?
2. and.. what is a parser combinator?

So first question: What is parser?

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The Best of the Best Practices (BOBP) Guide for Python

A "Best of the Best Practices" (BOBP) guide to developing in Python.

In General

Values

• "Build tools for others that you want to be built for you." - Kenneth Reitz
• "Simplicity is alway better than functionality." - Pieter Hintjens

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@echo off

if _%1_==__ goto USAGE

openssl req -x509 -nodes -days 365 -newkey rsa:1024 -keyout mycert.pem -out mycert.pem -subj "/CN=My Cert Name"
openssl pkcs12 -export -out mycert.pfx -inkey mycert.pem -in mycert.pem -passout pass:%1
openssl x509 -inform pem -in mycert.pem -outform der -out mycert.cer

openssl pkcs12 -in mycert.pfx -nodes -passin pass:%1 | openssl x509 -noout -fingerprint
openssl x509 -in mycert.pem -noout -fingerprint

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import contextlib
import OpenSSL.crypto
import os
import requests
import ssl
import tempfile

@contextlib.contextmanager
def pfx_to_pem(pfx_path, pfx_password):
    ''' Decrypts the .pfx file to be used with requests. '''

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import java.util.ArrayList;

class Solution
{
    public int solution(int[] H)
    {
        // rules
        /*
        * so when we find two indices that are of the same height, we can use the same block, providing all the values in-between are higher.
        *

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import sys

def factorial(n):
    if n == 0:
        return 1
    else:
        return n * factorial(n - 1)

def choose(n, m):
    return factorial(n) / (factorial(m) * factorial(n - m))

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"""
Port of nanoparsec in typed python from https://github.com/sdiehl/write-you-a-haskell/blob/master/chapter3/parsec.hs.

pip install attrs mypy
"""

from typing import Callable, Sequence, Text, Tuple, TypeVar

import attr

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class Automaton:
    def __init__(self, nstates):
        self.transitions = [{} for i in range(nstates)]
        self.accept_states = [False] * nstates

    def register(self, source_state, char, target_state):
        self.transitions[source_state][char] = target_state

    def register_accept(self, state):
        self.accept_states[state] = True

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#!/usr/bin/env python
import random
import operator
import time
from collections import OrderedDict
import unittest

class ordered_dict(dict):
    def __init__(self):
        self.order = {}

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# Located in Lib/collections/__init__.py

################################################################################
### OrderedDict
################################################################################

class _OrderedDictKeysView(KeysView):

    def __reversed__(self):
        yield from reversed(self._mapping)