ch03: wip

03-dict-set/03-dict-set.ipynb

@@ -0,0 +1,385 @@
+{
+ "cells": [
+  {
+   "cell_type": "code",
+   "execution_count": 1,
+   "metadata": {},
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "3.8.0 (v3.8.0:fa919fdf25, Oct 14 2019, 10:23:27) \n",
+      "[Clang 6.0 (clang-600.0.57)]\n"
+     ]
+    }
+   ],
+   "source": [
+    "import sys\n",
+    "print(sys.version)"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 2,
+   "metadata": {},
+   "outputs": [
+    {
+     "data": {
+      "text/plain": [
+       "True"
+      ]
+     },
+     "execution_count": 2,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "from collections import abc\n",
+    "my_dict = {}\n",
+    "isinstance(my_dict, abc.Mapping)"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 3,
+   "metadata": {},
+   "outputs": [
+    {
+     "data": {
+      "text/plain": [
+       "True"
+      ]
+     },
+     "execution_count": 3,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "isinstance(my_dict, abc.MutableMapping)"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 4,
+   "metadata": {},
+   "outputs": [
+    {
+     "data": {
+      "text/plain": [
+       "-3907003130834322577"
+      ]
+     },
+     "execution_count": 4,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "tt = (1, 2, (30, 40))\n",
+    "hash(tt)"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 7,
+   "metadata": {},
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "unhashable type: 'list'\n"
+     ]
+    }
+   ],
+   "source": [
+    "tl = (1, 2, [30, 40])\n",
+    "try:\n",
+    "    hash(tl)\n",
+    "except TypeError as e:\n",
+    "    print(e)"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 5,
+   "metadata": {},
+   "outputs": [
+    {
+     "data": {
+      "text/plain": [
+       "5149391500123939311"
+      ]
+     },
+     "execution_count": 5,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "tf = (1, 2, frozenset([30, 40]))\n",
+    "hash(tf)"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 8,
+   "metadata": {},
+   "outputs": [
+    {
+     "data": {
+      "text/plain": [
+       "True"
+      ]
+     },
+     "execution_count": 8,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "a = dict(one=1, two=2, three=3)\n",
+    "b = {'three': 3, 'two': 2, 'one': 1}\n",
+    "c = dict([('two', 2), ('one', 1), ('three', 3)])\n",
+    "d = dict(zip(['one', 'two', 'three'], [1, 2, 3]))\n",
+    "e = dict({'three': 3, 'one': 1, 'two': 2})\n",
+    "a == b == c == d == e"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 10,
+   "metadata": {},
+   "outputs": [
+    {
+     "data": {
+      "text/plain": [
+       "{'one': 1, 'two': 2, 'three': 3}"
+      ]
+     },
+     "execution_count": 10,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "a"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 11,
+   "metadata": {},
+   "outputs": [
+    {
+     "data": {
+      "text/plain": [
+       "['one', 'two', 'three']"
+      ]
+     },
+     "execution_count": 11,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "list(a.keys())"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 12,
+   "metadata": {},
+   "outputs": [
+    {
+     "data": {
+      "text/plain": [
+       "{'two': 2, 'one': 1, 'three': 3}"
+      ]
+     },
+     "execution_count": 12,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "c"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 13,
+   "metadata": {},
+   "outputs": [
+    {
+     "data": {
+      "text/plain": [
+       "('three', 3)"
+      ]
+     },
+     "execution_count": 13,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "c.popitem()"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 14,
+   "metadata": {},
+   "outputs": [
+    {
+     "data": {
+      "text/plain": [
+       "{'two': 2, 'one': 1}"
+      ]
+     },
+     "execution_count": 14,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "c"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 15,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "dial_codes = [                                                  # <1>\n",
+    "    (880, 'Bangladesh'),\n",
+    "    (55,  'Brazil'),\n",
+    "    (86,  'China'),\n",
+    "    (91,  'India'),\n",
+    "    (62,  'Indonesia'),\n",
+    "    (81,  'Japan'),\n",
+    "    (234, 'Nigeria'),\n",
+    "    (92,  'Pakistan'),\n",
+    "    (7,   'Russia'),\n",
+    "    (1,   'United States'),\n",
+    "]"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 17,
+   "metadata": {},
+   "outputs": [
+    {
+     "data": {
+      "text/plain": [
+       "{'Bangladesh': 880,\n",
+       " 'Brazil': 55,\n",
+       " 'China': 86,\n",
+       " 'India': 91,\n",
+       " 'Indonesia': 62,\n",
+       " 'Japan': 81,\n",
+       " 'Nigeria': 234,\n",
+       " 'Pakistan': 92,\n",
+       " 'Russia': 7,\n",
+       " 'United States': 1}"
+      ]
+     },
+     "execution_count": 17,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "country_dial = {country: code for code, country in dial_codes}\n",
+    "country_dial"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 18,
+   "metadata": {},
+   "outputs": [
+    {
+     "data": {
+      "text/plain": [
+       "{55: 'BRAZIL', 62: 'INDONESIA', 7: 'RUSSIA', 1: 'UNITED STATES'}"
+      ]
+     },
+     "execution_count": 18,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "{code: country.upper() \n",
+    "    for country, code in sorted(country_dial.items())\n",
+    "    if code < 70}"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 20,
+   "metadata": {},
+   "outputs": [
+    {
+     "data": {
+      "text/plain": [
+       "{'Pakistan': 92,\n",
+       " 'Indonesia': 62,\n",
+       " 'Russia': 7,\n",
+       " 'Japan': 81,\n",
+       " 'United States': 1,\n",
+       " 'China': 86,\n",
+       " 'Brazil': 55,\n",
+       " 'Bangladesh': 880,\n",
+       " 'Nigeria': 234,\n",
+       " 'India': 91}"
+      ]
+     },
+     "execution_count": 20,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "from random import shuffle\n",
+    "shuffle(dial_codes)\n",
+    "country_dial = {country: code for code, country in dial_codes}\n",
+    "country_dial"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": []
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "Python 3",
+   "language": "python",
+   "name": "python3"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 3
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython3",
+   "version": "3.8.0"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 2
+}

03-dict-set/README.md

@@ -0,0 +1,21 @@
+# Dictionaries and Sets
+
+Sample code for Chapter 3 of _Fluent Python 2e_ by Luciano Ramalho (O'Reilly, 2020)
+
+## Running the tests
+
+### Doctests
+
+Use Python's standard ``doctest`` module, for example:
+
+    $ python3 -m doctest bisect_demo.py -v
+
+### Jupyter Notebook
+
+Install ``pytest`` and the ``nbval`` plugin:
+
+    $ pip install pytest nbval
+
+Run:
+
+    $ pytest --nbval

03-dict-set/README.rst

@@ -1,4 +0,0 @@
-Sample code for Chapter 3 - "Dictionaries and sets"
-
-From the book "Fluent Python" by Luciano Ramalho (O'Reilly, 2015)
-http://shop.oreilly.com/product/0636920032519.do

03-dict-set/transformdict.py

@@ -3,10 +3,9 @@
 This module and ``test_transformdict.py`` were extracted from a
 patch contributed to Python by Antoine Pitrou implementing his
 PEP 455 -- Adding a key-transforming dictionary to collections.
-
-As of Nov. 14, 2014, the patch was not yet merged to Python 3.5
-(which is in pre-alpha). The patch is ``transformdict3.patch``,
-part of issue #18986: Add a case-insensitive case-preserving dict.
+That PEP was rejected, and the patch was never merged to CPython.
+The original code is in ``transformdict3.patch``, part of
+issue #18986: Add a case-insensitive case-preserving dict.
 
 http://bugs.python.org/issue18986
 """

03-dict-set/zen.txt

@@ -0,0 +1,21 @@
+The Zen of Python, by Tim Peters
+
+Beautiful is better than ugly.
+Explicit is better than implicit.
+Simple is better than complex.
+Complex is better than complicated.
+Flat is better than nested.
+Sparse is better than dense.
+Readability counts.
+Special cases aren't special enough to break the rules.
+Although practicality beats purity.
+Errors should never pass silently.
+Unless explicitly silenced.
+In the face of ambiguity, refuse the temptation to guess.
+There should be one-- and preferably only one --obvious way to do it.
+Although that way may not be obvious at first unless you're Dutch.
+Now is better than never.
+Although never is often better than *right* now.
+If the implementation is hard to explain, it's a bad idea.
+If the implementation is easy to explain, it may be a good idea.
+Namespaces are one honking great idea -- let's do more of those!