labs/Module-2/3.Statements/06-List Comprehensions.ipynb

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    "# List Comprehensions\n",
    "\n",
    "In addition to sequence operations and list methods, Python includes a more advanced operation called a list comprehension.\n",
    "\n",
    "List comprehensions allow us to build out lists using a different notation. You can think of it as essentially a one line <code>for</code> loop built inside of brackets. For a simple example:\n",
    "## Example 1"
   ]
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   "source": [
    "# Grab every letter in string\n",
    "lst = [x for x in 'word']"
   ]
  },
  {
   "cell_type": "code",
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   "source": [
    "# Check\n",
    "lst"
   ]
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    "This is the basic idea of a list comprehension. If you're familiar with mathematical notation this format should feel familiar for example: x^2 : x in { 0,1,2...10 } \n",
    "\n",
    "Let's see a few more examples of list comprehensions in Python:\n",
    "## Example 2"
   ]
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   "source": [
    "# Square numbers in range and turn into list\n",
    "lst = [x**2 for x in range(0,11)]"
   ]
  },
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   "cell_type": "code",
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    "lst"
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    "## Example 3\n",
    "Let's see how to add in <code>if</code> statements:"
   ]
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    "# Check for even numbers in a range\n",
    "lst = [x for x in range(11) if x % 2 == 0]"
   ]
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   "cell_type": "code",
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    "## Example 4\n",
    "Can also do more complicated arithmetic:"
   ]
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   "source": [
    "# Convert Celsius to Fahrenheit\n",
    "celsius = [0,10,20.1,34.5]\n",
    "\n",
    "fahrenheit = [((9/5)*temp + 32) for temp in celsius ]\n",
    "\n",
    "fahrenheit"
   ]
  },
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   "source": [
    "## Example 5\n",
    "We can also perform nested list comprehensions, for example:"
   ]
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   "outputs": [],
   "source": [
    "lst = [ x**2 for x in [x**2 for x in range(11)]]\n",
    "lst"
   ]
  },
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   "source": [
    "Later on in the course we will learn about generator comprehensions. After this lecture you should feel comfortable reading and writing basic list comprehensions."
   ]
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