lambda, map, filter, reduce.ipynb

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   "source": [
    "# Lambda\n",
    "Lambdas are one line functions. They are also known as anonymous functions in some other languages. You might want to use lambdas when you don’t want to use a function twice in a program. They are just like normal functions and even behave like them.  \n",
    "Signature: lambda argument : manipulate(argument)"
   ]
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     "text": [
      "4\n"
     ]
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   ],
   "source": [
    "# A function that prints its parameter\n",
    "toPrint = lambda e : print(e)\n",
    "toPrint(4)"
   ]
  },
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   "source": [
    "#### Lambda that adds 2 variables"
   ]
  },
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     "text": [
      "9\n",
      "3\n"
     ]
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   "source": [
    "# Method 1\n",
    "add1 = lambda a,b: a + b\n",
    "print(add1(4,5))\n",
    "\n",
    "# Method 2\n",
    "add2 = lambda a : lambda b: a + b \n",
    "print(add2(1)(2))"
   ]
  },
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   "source": [
    "# MAP\n",
    "Applies a function(can be a lambda function) to all the items in an input_list"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 28,
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     "text": [
      "[0, 1, 2, 3, 4, 5, 6, 7, 8, 9]\n",
      "[1, 2, 3, 4, 5, 6, 7, 8, 9, 10]\n"
     ]
    }
   ],
   "source": [
    "mylist = list(range(10))\n",
    "print(mylist)\n",
    "\n",
    "#lets add 1 to eache element\n",
    "myNewList = list(map(lambda x: x + 1 ,mylist))\n",
    "print(myNewList)"
   ]
  },
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   "source": [
    "## Filter\n",
    "Creates a list of elements for which a function returns true"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 59,
   "metadata": {},
   "outputs": [
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     "name": "stdout",
     "output_type": "stream",
     "text": [
      "[-5, -4, -3, -2, -1]\n"
     ]
    }
   ],
   "source": [
    "number_list = range(-5, 5)\n",
    "less_than_zero = list(filter(lambda x: x < 0, number_list))\n",
    "print(less_than_zero)\n"
   ]
  },
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   "metadata": {},
   "source": [
    "## Reduce\n",
    "Perform some computation on a list and returning the result."
   ]
  },
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     "text": [
      "24\n"
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   "source": [
    "from functools import reduce\n",
    "product = reduce((lambda x, y: x * y), [1, 2, 3, 4])\n",
    "print ( product )\n",
    "\n",
    "employee = {\n",
    "    'cope': 6456,\n",
    "    'asge': 6852, \n",
    "    'dima': 6835, \n",
    "    'wwaa': 6168, \n",
    "}\n",
    "\n",
    "# How much is the total amount of money paid for salary concept?\n",
    "reduce(lambda e,m: e + m ,list(employee.values()))\n"
   ]
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