01_anaconda.ipynb

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   "cell_type": "markdown",
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   "source": [
    "# Anaconda: working with packages\n",
    "\n",
    "## Importing packages\n",
    "\n",
    "By convention, imports go at the top of a Python script or notebook (see [PEP 8](https://www.python.org/dev/peps/pep-0008/#imports)). In relevant part:\n",
    "\n",
    ">Imports are always put at the top of the file, just after any module comments and docstrings, and before module globals and constants.\n",
    "\n",
    ">Imports should be grouped in the following order:\n",
    "\n",
    ">    - Standard library imports.\n",
    ">    - Related third party imports.\n",
    ">    - Local application/library specific imports.\n",
    "\n",
    ">You should put a blank line between each group of imports.\n",
    "\n"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 1,
   "metadata": {},
   "outputs": [],
   "source": [
    "# standard library\n",
    "import sys\n",
    "\n",
    "# third party\n",
    "import pandas as pd\n",
    "from textblob import TextBlob"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "Note a few things in the block above.\n",
    "\n",
    "1. The `import sys` is the simplest version.\n",
    "2. For some things we use a lot (and also by convention), we would like to abbreviate the names of some packages. For example, `pandas` is often imported as `pd`, both because it is used often and also by convention (see [pandas documentation](https://pandas.pydata.org/pandas-docs/stable/dsintro.html)).\n",
    "3. We can also import particular things from a package, like the class `TextBlob` from the package `textblob`.\n",
    "\n",
    "Let's see how these work in action."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 4,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "/Users/jkiley/anaconda3/envs/workshop/bin/python\n"
     ]
    }
   ],
   "source": [
    "print(sys.executable)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "Note that to find the contents of this attribute `executable` within the `sys` package, we have to use the package namespace `sys`. Most about namespaces below."
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## Namespaces\n",
    "\n",
    "Somewhat abstactly, the [python docs](https://docs.python.org/3.6/tutorial/classes.html#python-scopes-and-namespaces) define a namespace as follows.\n",
    "\n",
    "> A namespace is a mapping from names to objects.\n",
    "\n",
    "For our purposes, we can think of them as paths to get to tools of interest. This topic goes (much) deeper, but a more instrumental understanding is fine for our use.\n",
    "\n",
    "If we want to know what is contained in a namespace, we can easily find out with the `dir()` built-in function."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 6,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "['__displayhook__',\n",
       " '__doc__',\n",
       " '__excepthook__',\n",
       " '__interactivehook__',\n",
       " '__loader__',\n",
       " '__name__',\n",
       " '__package__',\n",
       " '__spec__',\n",
       " '__stderr__',\n",
       " '__stdin__',\n",
       " '__stdout__',\n",
       " '_clear_type_cache',\n",
       " '_current_frames',\n",
       " '_debugmallocstats',\n",
       " '_getframe',\n",
       " '_git',\n",
       " '_home',\n",
       " '_xoptions',\n",
       " 'abiflags',\n",
       " 'api_version',\n",
       " 'argv',\n",
       " 'base_exec_prefix',\n",
       " 'base_prefix',\n",
       " 'builtin_module_names',\n",
       " 'byteorder',\n",
       " 'call_tracing',\n",
       " 'callstats',\n",
       " 'copyright',\n",
       " 'displayhook',\n",
       " 'dont_write_bytecode',\n",
       " 'exc_info',\n",
       " 'excepthook',\n",
       " 'exec_prefix',\n",
       " 'executable',\n",
       " 'exit',\n",
       " 'flags',\n",
       " 'float_info',\n",
       " 'float_repr_style',\n",
       " 'get_asyncgen_hooks',\n",
       " 'get_coroutine_wrapper',\n",
       " 'getallocatedblocks',\n",
       " 'getcheckinterval',\n",
       " 'getdefaultencoding',\n",
       " 'getdlopenflags',\n",
       " 'getfilesystemencodeerrors',\n",
       " 'getfilesystemencoding',\n",
       " 'getprofile',\n",
       " 'getrecursionlimit',\n",
       " 'getrefcount',\n",
       " 'getsizeof',\n",
       " 'getswitchinterval',\n",
       " 'gettrace',\n",
       " 'hash_info',\n",
       " 'hexversion',\n",
       " 'implementation',\n",
       " 'int_info',\n",
       " 'intern',\n",
       " 'is_finalizing',\n",
       " 'last_traceback',\n",
       " 'last_type',\n",
       " 'last_value',\n",
       " 'maxsize',\n",
       " 'maxunicode',\n",
       " 'meta_path',\n",
       " 'modules',\n",
       " 'path',\n",
       " 'path_hooks',\n",
       " 'path_importer_cache',\n",
       " 'platform',\n",
       " 'prefix',\n",
       " 'ps1',\n",
       " 'ps2',\n",
       " 'ps3',\n",
       " 'set_asyncgen_hooks',\n",
       " 'set_coroutine_wrapper',\n",
       " 'setcheckinterval',\n",
       " 'setdlopenflags',\n",
       " 'setprofile',\n",
       " 'setrecursionlimit',\n",
       " 'setswitchinterval',\n",
       " 'settrace',\n",
       " 'stderr',\n",
       " 'stdin',\n",
       " 'stdout',\n",
       " 'thread_info',\n",
       " 'version',\n",
       " 'version_info',\n",
       " 'warnoptions']"
      ]
     },
     "execution_count": 6,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "dir(sys)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "While we might think of namespaces as synonymous with packages, it's more general than that.\n",
    "Individual objects have their own namespaces, like the `TextBlob` class we imported earlier."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 10,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "['__add__',\n",
       " '__class__',\n",
       " '__contains__',\n",
       " '__delattr__',\n",
       " '__dict__',\n",
       " '__dir__',\n",
       " '__doc__',\n",
       " '__eq__',\n",
       " '__format__',\n",
       " '__ge__',\n",
       " '__getattribute__',\n",
       " '__getitem__',\n",
       " '__gt__',\n",
       " '__hash__',\n",
       " '__init__',\n",
       " '__init_subclass__',\n",
       " '__iter__',\n",
       " '__le__',\n",
       " '__len__',\n",
       " '__lt__',\n",
       " '__module__',\n",
       " '__ne__',\n",
       " '__new__',\n",
       " '__reduce__',\n",
       " '__reduce_ex__',\n",
       " '__repr__',\n",
       " '__setattr__',\n",
       " '__sizeof__',\n",
       " '__str__',\n",
       " '__subclasshook__',\n",
       " '__weakref__',\n",
       " '_cmpkey',\n",
       " '_compare',\n",
       " '_create_sentence_objects',\n",
       " '_strkey',\n",
       " 'analyzer',\n",
       " 'classify',\n",
       " 'correct',\n",
       " 'detect_language',\n",
       " 'ends_with',\n",
       " 'endswith',\n",
       " 'find',\n",
       " 'format',\n",
       " 'index',\n",
       " 'join',\n",
       " 'json',\n",
       " 'lower',\n",
       " 'ngrams',\n",
       " 'noun_phrases',\n",
       " 'np_counts',\n",
       " 'np_extractor',\n",
       " 'parse',\n",
       " 'parser',\n",
       " 'polarity',\n",
       " 'pos_tagger',\n",
       " 'pos_tags',\n",
       " 'raw_sentences',\n",
       " 'replace',\n",
       " 'rfind',\n",
       " 'rindex',\n",
       " 'sentences',\n",
       " 'sentiment',\n",
       " 'sentiment_assessments',\n",
       " 'serialized',\n",
       " 'split',\n",
       " 'starts_with',\n",
       " 'startswith',\n",
       " 'strip',\n",
       " 'subjectivity',\n",
       " 'tags',\n",
       " 'title',\n",
       " 'to_json',\n",
       " 'tokenize',\n",
       " 'tokenizer',\n",
       " 'tokens',\n",
       " 'translate',\n",
       " 'translator',\n",
       " 'upper',\n",
       " 'word_counts',\n",
       " 'words']"
      ]
     },
     "execution_count": 10,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "dir(TextBlob)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "We can also look at what is in the global namespace."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 9,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "['In',\n",
       " 'Out',\n",
       " 'TextBlob',\n",
       " '_',\n",
       " '_6',\n",
       " '_7',\n",
       " '_8',\n",
       " '__',\n",
       " '___',\n",
       " '__builtin__',\n",
       " '__builtins__',\n",
       " '__doc__',\n",
       " '__loader__',\n",
       " '__name__',\n",
       " '__package__',\n",
       " '__spec__',\n",
       " '_dh',\n",
       " '_i',\n",
       " '_i1',\n",
       " '_i2',\n",
       " '_i3',\n",
       " '_i4',\n",
       " '_i5',\n",
       " '_i6',\n",
       " '_i7',\n",
       " '_i8',\n",
       " '_i9',\n",
       " '_ih',\n",
       " '_ii',\n",
       " '_iii',\n",
       " '_oh',\n",
       " 'exit',\n",
       " 'get_ipython',\n",
       " 'pd',\n",
       " 'quit',\n",
       " 'sys',\n",
       " 'this']"
      ]
     },
     "execution_count": 9,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "dir()"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "Note that we see the `sys` and `pd` packages that we imported, and we also see the `TextBlob` class that we imported from its package."
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## import this\n",
    "\n",
    "A fun import is The Zen of Python philosophy, which can be accessed by importing `this`. \n",
    "Note that I'm slightly breaking the rules above for the purposes of illustration."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 3,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "The Zen of Python, by Tim Peters\n",
      "\n",
      "Beautiful is better than ugly.\n",
      "Explicit is better than implicit.\n",
      "Simple is better than complex.\n",
      "Complex is better than complicated.\n",
      "Flat is better than nested.\n",
      "Sparse is better than dense.\n",
      "Readability counts.\n",
      "Special cases aren't special enough to break the rules.\n",
      "Although practicality beats purity.\n",
      "Errors should never pass silently.\n",
      "Unless explicitly silenced.\n",
      "In the face of ambiguity, refuse the temptation to guess.\n",
      "There should be one-- and preferably only one --obvious way to do it.\n",
      "Although that way may not be obvious at first unless you're Dutch.\n",
      "Now is better than never.\n",
      "Although never is often better than *right* now.\n",
      "If the implementation is hard to explain, it's a bad idea.\n",
      "If the implementation is easy to explain, it may be a good idea.\n",
      "Namespaces are one honking great idea -- let's do more of those!\n"
     ]
    }
   ],
   "source": [
    "import this"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "# Alternative interfaces for Python.\n",
    "\n",
    "As we'll talk about later, Jupyter notebooks are a great interface for working with Python (or R or a number of other kernels).\n",
    "However, they are not the only game in town.\n",
    "\n",
    "1. **Python interpreter.** We can access the Python interpreter from the terminal.\n",
    "2. **Running a script from the terminal.** We can also make our own script and run it from the terminal."
   ]
  }
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