420_Filter.ipynb

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    "# Filter\n",
    "\n",
    "The `filter()` function that Python gives us is great for performing a logic check on an item in a list (or other iterable type like a tuple). It simply does a yes/no check (by returning True/False) and anything that's True is kept. "
   ]
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    "def filter_even_numbers(num):\n",
    "    \"\"\"\n",
    "    Returns only even numbers\n",
    "    \"\"\"\n",
    "    return num % 2 == 0"
   ]
  },
  {
   "cell_type": "code",
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   "metadata": {},
   "outputs": [],
   "source": [
    "nums = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14]"
   ]
  },
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     "text": [
      "2\n",
      "4\n",
      "6\n",
      "8\n",
      "10\n",
      "12\n",
      "14\n"
     ]
    }
   ],
   "source": [
    "for num in filter(filter_even_numbers, nums):\n",
    "    print(num)"
   ]
  },
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   "cell_type": "code",
   "execution_count": 7,
   "metadata": {},
   "outputs": [],
   "source": [
    "evens = list(filter(filter_even_numbers, nums))"
   ]
  },
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   "cell_type": "code",
   "execution_count": 8,
   "metadata": {},
   "outputs": [
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     "data": {
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       "[2, 4, 6, 8, 10, 12, 14]"
      ]
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     "execution_count": 8,
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   ],
   "source": [
    "evens"
   ]
  },
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   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "> **Note:** Like in the `map()` lesson, we've type casted the `filter()` results to a `list` so we can access all the answers all at once. This is helpful when working with Generators, which we'll learn about in the future!"
   ]
  }
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