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   "source": [
    "A lambda function: \n",
    "* is a small anonymous function.\n",
    "* can take any number of arguments\n",
    "* can only have one expression.\n",
    "\n",
    "sintaxe:\n",
    "\n",
    "    lambda arguments : expression"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "1. Exemplo with one argument"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "a = lambda x : x + 20"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "print(a(2))"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "2. Non lambda function alternative"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "def aAlt(x):\n",
    "    return x+20"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "print(aAlt(2))"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "3. Exemplo with one argument"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "\n",
    "b = lambda x, y : x * y\n"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "print(b(10,20)) "
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "4. Non lambda function alternative"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "# alterantive\n",
    "def bAlt(x,y):\n",
    "    return x*y"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "print(bAlt(10,20)) "
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "The power of lambda is better shown when you use them as an anonymous function inside another function.\n"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "5. We have function definition that takes one argument, and that argument will be multiplied with an unknown number."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "def myFunc(n):\n",
    "  return lambda a : a * n "
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "doubling = myFunc(2)\n",
    "tripling = myFunc(3)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "print(tripling(11))"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "6. The filter function is used to select some particular elements from a sequence of elements. \n",
    "The sequence can be any iterator like lists, sets, tuples, etc. lambdas in filter()"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "sequences = [2,3,6,7,1,1,8]\n",
    "filteredResult = filter (lambda x: x > 4, sequences) \n",
    "list(filteredResult)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "7. the map function is used to apply a particular operation to every element in a sequence. Like filter(), it also takes 2 parameters: a function that defines the operation to perform on the elements, and one or more sequences. The follwoing program prints the squares of numbers in the previous list: "
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "filteredResult1 = map (lambda x: x**2, sequences) \n",
    "print(list(filteredResult1))"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": []
  }
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